Aurora 4x

VB6 Aurora => Advanced Tactical Command Academy => Topic started by: GetStqned on September 17, 2016, 12:16:46 PM

Title: I think I create too slow missiles
Post by: GetStqned on September 17, 2016, 12:16:46 PM
I have Magnetic Fusion Drive Technology , and that's is the design of my missile...

Missile Size: 4.97 MSP  (0.2485 HS)     Warhead: 12    Armour: 0     Manoeuvre Rating: 32
Speed: 14700 km/s    Engine Endurance: 6.7 hours   Range: 354.3m km
Cost Per Missile: 6.0872
Chance to Hit: 1k km/s 470.4%   3k km/s 128%   5k km/s 94.1%   10k km/s 47%
Materials Required:    3x Tritanium   3.0872x Gallicite   Fuel x275

Development Cost for Project: 609RP


For as advanced technology, 14700 km/s is not much right?
I found an enemy I easily beat them over 20 or 10 years, I beat the two ships with 20 missiles to a single ship , my older missile design advancing at 9000km / s , and i finish by "atomize their colony" , they are not reappeared , then one day one of my exploration ship encounter on of them with missiles advancing at 45000km/s !! while technological inferiority was then disembark before my fleet , I would know where I screwed up, for the missile engine : (i don't know chere i find the design so so I'll give you the info from View Technology)
3.645 EP Magnectic Fusion Drive
Size : 2.16
Cost : Who care ?
Power: 3.645
Fuem Efficiency : 11.27
Title: Re: I think I create too slow missiles
Post by: Tree on September 17, 2016, 12:41:15 PM
Put in less fuel, a smaller warhead (like 4 or 9), less maneuver rating and put on your max power/efficiency modifier on the engine. A range of 100~150mkm should be good enough.
Less fuel because your range is enormous and not worth the low speed.
Warheads of 4 or 9 because they have better damage templates for penetration (a warhead of 4 would destroy 3 box of armor off the first layer and one off the second, one of 9 would destroy 5 boxes on the first layer, 3 on the second, and one on the third) which would allow you to hit the target's innards for cheaper and with greater speed.
Maneuver rating isn't useless, but hit chance depends on both it and speed, there are a lot of interesting sweet spots, you could have a much greater speed with lower maneuver for similar enough chances to hit, try messing with it. You can get interesting results even with a maneuver rating of 10~15 if you have a high enough speed.
The lower range would be there just because of the modifications, you just can't get it all. But it's better to have a lower range and higher chances to hit than the opposite, I think.

And with magnetic confinement fusion drive tech, ~15000km/s should really more be the speed of your military ships rather than that of your missiles.
Title: Re: I think I create too slow missiles
Post by: GetStqned on September 17, 2016, 01:04:01 PM
15000 km/s for my ships ? oO I have 25000t ships with a speed of 3376 km/s , my fastest ship have a tonnage of 15000t and advance at 5626 km/s , I need what tonnage with what louse boost engines for ships has 15000 km/s ? * _ * , For missiles I will follow your advice thank you

EDIT : Just a think i forget , the power boost modifiers i use is 2.22 , i need to put more ? I was afraid that fuel consumption becomes too large , it is already tight with 2.22 so with more...
Title: Re: I think I create too slow missiles
Post by: Xkill on September 17, 2016, 03:17:43 PM
When I design ships or missiles, I like to reserve a percentage of the vehicle's mass to the engines as it makes it easier to design them since I don't need to keep worrying about speed. It also tends to make speeds equal across the fleet. I'd say that you should aim for around 20%~50% for both ships and missiles, depending on what role you have in mind for them.

Here's an example of a missile designed with MagPlasma tech, 5x power modifier and 0.6 fuel efficiency:

Quote
Code: [Select]
Missile Size: 5 MSP  (0.25 HS)     Warhead: 7    Armour: 0     Manoeuvre Rating: 10
Speed: 40000 km/s    Engine Endurance: 42 minutes   Range: 100.3m km
Cost Per Missile: 4.25
Chance to Hit: 1k km/s 400%   3k km/s 130%   5k km/s 80%   10k km/s 40%
Materials Required:    1.75x Tritanium   2.5x Gallicite   Fuel x1875

Development Cost for Project: 425RP
Code: [Select]
Missile Size: 4.97 MSP  (0.2485 HS)     Warhead: 12    Armour: 0     Manoeuvre Rating: 32
Speed: 14700 km/s    Engine Endurance: 6.7 hours   Range: 354.3m km
Cost Per Missile: 6.0872
Chance to Hit: 1k km/s 470.4%   3k km/s 128%   5k km/s 94.1%   10k km/s 47%
Materials Required:    3x Tritanium   3.0872x Gallicite   Fuel x275

Development Cost for Project: 609RP

While you missiles are not that bad, (good range, accuracy and damage) they are very slow, which means they will be shot down very easily. Even the unturreted (slow tracking speed), Railgun flak PD on my ships would have a 42% chance of shooting one of your missiles down at point-blank range.

Assuming that you would be shooting at a 3 Frigate group of mine (3 guns per ship, firing 4 shots each for a total of 36 shots group wide) their PD would be able to shoot down 15 missiles of yours compared to just 5 of mine

Now the one I designed has almost equal accuracy, lower damage and far lower range, but they should be much harder to shoot down (and will therefore score more hits). The aforementioned PD has a 15% chance of shooting one of these down.
Title: Re: I think I create too slow missiles
Post by: GetStqned on September 17, 2016, 03:43:18 PM
Following your advice, I managed to make these missiles :

Missile Size: 4 MSP  (0.2 HS)     Warhead: 6    Armour: 0     Manoeuvre Rating: 28
Speed: 50000 km/s    Engine Endurance: 67 minutes   Range: 200.6m km
Cost Per Missile: 5.408
Chance to Hit: 1k km/s 1400%   3k km/s 448%   5k km/s 280%   10k km/s 140%
Materials Required:    1.5x Tritanium   3.908x Gallicite   Fuel x1000

Development Cost for Project: 541RP

faster , untouchable , powerful  thanks guys but that does not really answer my question for the engine missile is a smaller version then put the power boost modifiers at high levels is cool but with real military engine consumption becomes unbearable , there's a balance of value or a estimation between 20 and 10 something like that ?
Title: Re: I think I create too slow missiles
Post by: Iranon on September 17, 2016, 05:16:43 PM
With freely scaleable missile engines, your most efficient propulsion setup uses 31% of engine weight for fuel.
With a fixed engine size (ship or missile), your most efficient propulsion setup uses 40% of engine weight for fuel.
Short-ranged high-performance missiles will often use less fuel, because the sweet ratio with your highest power multiplier results in excessive range and you're rather have more speed.
Title: Re: I think I create too slow missiles
Post by: GetStqned on September 17, 2016, 06:27:08 PM
Thank you guys, I 'm going to test it , it gives new perspectives and I can already see the design in my head =D
Title: Re: I think I create too slow missiles
Post by: TallTroll on October 26, 2016, 02:43:34 PM
Although there are a lot of considerations, I generally devote about 50% of ASM missile space to engines, about 25% to WH, and the balance to AG / fuel. Once upon a time, someone did some maths and found that getting agility to 11 gets the best bang for your MSP (for ASMs. AMMs have different design constraints)
Title: Re: I think I create too slow missiles
Post by: alex_brunius on October 27, 2016, 04:50:43 AM
Once upon a time, someone did some maths and found that getting agility to 11 gets the best bang for your MSP (for ASMs. AMMs have different design constraints)

It's impossible to "do the math" on this one since they impact different things and both are thus "best bang for MSP" in different situations.

Take for example a slow target which you have 100% chance to hit due to your speed alone, but that has fairly fast tracking PD turrets. Any Agility at all in that case is useless and speed is what you need to lower the chance to have the missiles shot down.

Then compare it with the other example of the ASMs targeting very fast FAC/Fighters that don't have any point defense at all. As soon as your agility / MSP tech is above a certain amount more agility will then always be better then more speed ( assuming you got enough speed to catch them ).

So it's impossible to say that one or the other is better, it depends on your intended targets!
Title: Re: I think I create too slow missiles
Post by: TallTroll on October 27, 2016, 05:14:45 AM
>>  it depends on your intended targets!

The point of that exercise was that you were designing an ASM for use against unknown targets, not least because they may end up being ships that haven't even been designed, let alone built, at the time you are designing the missile. Given all the other design constraints on any missile, it is generally better to minimise the MSP devoted to agility (for ASMs at least), because speed is a higher order determinant of hit chances.

However, since any missile has a base agility of 10, paying for 1 extra AG gives the maximum benefit in terms of hit %age to MSP ratio. Paying for an upgrade to 20 AG costs 10x as much MSP, whilst only doubling the AG stat. Paying to go up to 11 gets you a 10% increase in performance, for 1/10th the MSP.

Obviously, if you have any information on the targets you want to fire the ASMs at, you can make much better assumptions about what performance you need / want, but in the case where you just have no idea at all, going to 11 AG will usually give better average results for the smallest investment of MSP
Title: Re: I think I create too slow missiles
Post by: Iranon on October 27, 2016, 05:20:58 AM
I did the math.
Ideal Agility MSP to maximise accuracy on a given weight budget for (engine + agility) is E-10S/A
where E is engine tonnage, S is total missile size, A is your agility rating per MSP
This will need to be adjusted for rounding issues, you want to hit (n+0,5)S agility points.

I'd use less in practice. More engine, less agility
- makes the missile faster, thus harder to intercept as alex_brunius stated. May have other advantages.
- increases range (assuming it means a bigger engine)
- is usually cheaper

My baseline is 40% engine, 30% warhead, 20% agility, 10% fuel. That's actually on the edge of too much agility, but keeps things simple: I know what to skimp on if I need to round the warhead up to a nice number or fit a sensor.
Title: Re: I think I create too slow missiles
Post by: TallTroll on October 27, 2016, 05:31:10 AM
>> Ideal Agility MSP to maximise accuracy on a given weight budget

That only applies in the case of wanting to maximise accuracy. For a totally blind design, maximising speed, whilst preserving some accuracy may be a better bet, since increased speed might allow you to engage a larger range of targets. If you have no information at all on what targets are out there, it might prove a better design target to prioritise missile speed.
Title: Re: I think I create too slow missiles
Post by: alex_brunius on October 27, 2016, 05:54:54 AM
That only applies in the case of wanting to maximise accuracy.

That was exactly my point.

Fine, you can maximize one stat or aspect of the missile (like accuracy) and do the math for that...

But you can't maximize "bang for the MSP", since that basically means you have to also juggle things like warhead size (the bang), chance PD will shoot down the missile, different target speeds, range (for fuel needs), and all other unknowns that make it a pointless exercise.


I do certainly agree with the general "When in doubt go for speed" approach though, since it's always helps with hitting the target ( even if agility helps more in some situations ).
Title: Re: I think I create too slow missiles
Post by: Iranon on October 27, 2016, 05:57:35 AM
...

Yes, as I already stated after the calculations.

The point of maximum accuracy is useful to know as an upper bound. Until we reach it, we have a trade-off between speed and accuracy.
More agility than that, and we lose both speed and accuracy: detrimental unless our needs specifically require a slow missile that still needs to hit moving targets.
Title: Re: I think I create too slow missiles
Post by: alex_brunius on October 27, 2016, 05:59:08 AM
Yes, as I already stated after the calculations.

I'm not replying to you. I'm replying to TallTroll.... ( who made the claim about a certain agility being the best bang for MSP ).
Title: Re: I think I create too slow missiles
Post by: TallTroll on October 27, 2016, 06:10:57 AM
>> ( who made the claim about a certain agility being the best bang for MSP ).

If you have no info on potential targets, I would always prioritise speed. An ASM that that would have 100% to-hit, but can't catch its' target is worse than a faster ASM that *could* catch its' target, but only has an 80% to-hit. Of course, once you do have some info on your potential opponents, you can design missiles optimised to fight them, since you will have some idea of their size and speed, at least.

I would argue that until then, designing ASMs for max speed and 11 AG is likely to be the superior design constraint, because it gives the highest flexibility. A player may choose different design constraints for other reasons, such as RP value, having a specific playstyle in mind from the start, or just because that's not how they like to design missiles. Aurora is a very catholic game in that way. Max speed / 11 AG is probably a more optimal build when you just don't know what's out there though. But, this is Aurora... when has "optimal" ever been everyones yardstick  ;D?
Title: Re: I think I create too slow missiles
Post by: Iranon on October 27, 2016, 06:47:43 AM
The fixation on "11 AG" makes no sense.

You shouldn't care how much you get "per point of agility spent".
If you'd like some apples and I give you a free sample, by your argument you'd never buy more than one - after all, the more you buy, the higher the price per apple.
This makes no sense, unless you can mooch freebies off multiple vendors, which you can't in the case of missile agility.
Title: Re: I think I create too slow missiles
Post by: alex_brunius on October 27, 2016, 06:54:33 AM
I would argue that until then, designing ASMs for max speed and 11 AG is likely to be the superior design constraint, because it gives the highest flexibility.

I'd argue that you never design missiles without knowing anything at all about the missiles intended targets. Same way you never design a single ship to do everything.

If I make a massive Warhead 50 missile I know I'm not going to use it against fighters for example... And opposite I know that an anti FAC/Fighter missile with a small warhead probably won't need to get through massive amount of PD and can put more priority on Agility instead to maximize accuracy/to hit.


If you design a single generic all purpose missile to "kill all stuff" your probably not playing Aurora at an advanced enough level to care a whole lot about math, formulas or targets anyway.
Title: Re: I think I create too slow missiles
Post by: TallTroll on October 27, 2016, 08:04:33 AM
I think you are missing the point here, although I may not have been explaining in enough depth, so here goes.

Consider the total possible design spaces for all possible ASMs, and all possible enemy vessels. There are certain design choices for you as the ASM designer that will produce better average outcomes in combat. In the specific case of having no info on enemy designs, one of those possible choices is prioritising speed, because that would allow you to better engage a larger proportion of all possible enemy designs, because the conditions for using ASMs successfully is that they can 1) catch the target, and 2) hit it. Clearly, the 2 conditions are fairly tightly bound, because both speed and AG contribute to final to-hit %age, but only speed contributes to condition 1). Having a high to-hit value is worthless if your ASM cannot in fact catch an intended target, thus one of the design considerations is how to allocate MSPs to maximise your ability to catch and hit a target of unknown performance and specs.

Therefore, one approach to ASM design is to maximise your speed. As we know, both speed and AG factor into the final to-hit calc though, so it seems likely that allocating some MSPs to AG will lead to better overall ASM performance. All missiles start with a base AG of 10. If we choose to allocate enough MSPs to increase that to 20, for instance, we use an amount of MSPs to double the AG stat and thus improve the to-hit value with a method independent of speed, but is there a better choice?

Enter the 11 AG break point. Instead of allocating MSPs sufficient to double the AG stat, we use enough to raise it to 11, getting a 10% increase for the commitment. Every subsequent commitment of the same amount of MSPs suffers from the law of diminishing returns, decreasing the benefit we gain overall. Going from 11 to 12 only nets us a gain of about 9%, rather than the 10% we got the first time, and so on until the increase from 19 to 20 is only gaining us ~5%, about half the benefit of that first commitment. Thus, setting AG to 11 is an "optimal" design choice, because it gains us the highest possible increase in overall to-hit, for the lowest investment of MSPs. Ideally, we would like to invest our MSPs in most efficient manner possible, because missiles are pretty expensive, and tie up valuable and irreplaceable resources.

Now, it may prove to be the case that there were better things we could have done with those MSPs, but to predict that we would need to have some idea of the stats of the vessels we would be shooting at, and one of the key assumptions of this design philosophy is that we don't. As I say, as soon as we have some info on enemy ships, we can start to design ASMs that counter them more efficiently, but since most games start with the player knowing little or nothing about enemy designs, it's worth considering.

Nothing in any of this places any absolute requirement to use this design philosophy, since as noted previously, you may be deliberately RPing a race that has other priorities, have other constraints like lack of certain resources or production capacity, or just decide that it isn't a design philosophy you want to use, but it remains the case that if you just don't know what is out there, using this approach is more likely to produce ASMs that are more useful against a larger range of potential targets, for the smallest investment of resources.

I'm not saying that 11 AG is a perfect solution for all situations by any means, but when you have no other info to go on, it provides a better general purpose solution than most other possible choices. Assuming that that is the kind of solution you are looking for, which it may not be... Missile design is sometimes an art as much as a science. That's why there are so many threads about it. The "perfect" solution is to design a specific hard-counter missile for every enemy ship class, but that involves other costs and problems that aren't reflected in the missile design screen, like magazine and ordnance loadout management, complex logistics, tying up finite resources in missiles that may never even see combat, and so on. Trading down to 11 AG for speed is just one approach which will probably be more beneficial for many players in many situations. Noone is going to be upset if you choose different priorities, for any reason or for none.

>> I'd argue that you never design missiles without knowing anything at all about the missiles intended targets.

Ideally, yes. If the first time you meet a given race is when their war fleet drops into Sol or a system one jump away or something, you might want some ordnance on hand though. So having some missiles would be better than having none. And having missiles that are more likely to be at least somewhat effective is generally better than having missiles specifically designed for the wrong target

>> If you design a single generic all purpose missile to "kill all stuff"

That's not what I'm saying at all. AMMs have different design constraints to ASMs for smaller targets, which have different constraints to ASMs for larger targets, which have different constraints to ASMs for long range combat, which  have different constraints to ASMs for short range combat etc, etc. Having a few fire units of general purpose ordnance on hand when you need them is better than being able to design a perfect hard counter ASM too late, and getting your planets nuked before you can build any "good" missiles
Title: Re: I think I create too slow missiles
Post by: alex_brunius on October 27, 2016, 08:46:22 AM
Ideally, yes. If the first time you meet a given race is when their war fleet drops into Sol or a system one jump away or something, you might want some ordnance on hand though. So having some missiles would be better than having none. And having missiles that are more likely to be at least somewhat effective is generally better than having missiles specifically designed for the wrong target

How does having no missiles have anything to do with it?

The choice here is between having a few different types of missiles that perform well in certain roles against different types of targets, and having a generic one size fits all missile.

Since missile engines and missiles are such small components the more specialized ones cost you almost nothing extra to research or build, and you can allow you to cover both cases of missiles which are fast and good at defeating heavy PD, and missiles which are agile and good at defeating faster FAC/Fighters or targets without PD.

That's not what I'm saying at all. AMMs have different design constraints to ASMs for smaller targets, which have different constraints to ASMs for larger targets, which have different constraints to ASMs for long range combat, which  have different constraints to ASMs for short range combat etc, etc. Having a few fire units of general purpose ordnance on hand when you need them is better than being able to design a perfect hard counter ASM too late, and getting your planets nuked before you can build any "good" missiles

Where did I argue you should wait and design the ASMs to counter specific alien designs?

The first thing I wrote was that you can design missiles against generic target types without knowing anything about your enemy ( or even having met them ).

If you have to use them against the "wrong" target they will not be performing worse then a compromise "one size fits all" design will, which also is not tailored against the target.

They will however perform better when they are used against their intended target, so there is no downside to the approach.
Title: Re: I think I create too slow missiles
Post by: 83athom on October 27, 2016, 10:57:17 AM
The choice here is between having a few different types of missiles that perform well in certain roles against different types of targets, and having a generic one size fits all missile.
There is also the option of having a few types of generic missiles to fit certain conditions (like range).
The first thing I wrote was that you can design missiles against generic target types without knowing anything about your enemy ( or even having met them ).
Newer players can't really do that as they don't really expect what kin of things they may go against before they do.
If you have to use them against the "wrong" target they will not be performing worse then a compromise "one size fits all" design will, which also is not tailored against the target.
This is highly circumstantial. Sometimes using a specialized missile against the "wrong" target has the same effectiveness as a generic. Other times it is worse off. It depends on the specialized missile, the generic missile, and the enemy that it is hitting.
They will however perform better when they are used against their intended target, so there is no downside to the approach.
A misrepresentation using the "because there is an upside, there is no downside" way of thinking.

1) catch the target, and 2) hit it. Clearly, the 2 conditions are fairly tightly bound, because both speed and AG contribute to final to-hit %age, but only speed contributes to condition 1).
Not necessarily. While that is true against enemies headed in the opposite direction, it does not apply to enemies headed directly at you or sitting still. I've had plenty of cases in my own games where I have been hit by surprise missiles that were slower than my ships, and where I've hit enemies who were faster than my missiles.
Having a high to-hit value is worthless if your ASM cannot in fact catch an intended target, thus one of the design considerations is how to allocate MSPs to maximise your ability to catch and hit a target of unknown performance and specs.
Just because you sacrifise some MSP % from engines and put it into agility, does not mean it will not catch the enemy. Your argument seems to be based on sacrificing most of your engines to put into agility.
Therefore, one approach to ASM design is to maximise your speed. As we know, both speed and AG factor into the final to-hit calc though, so it seems likely that allocating some MSPs to AG will lead to better overall ASM performance. All missiles start with a base AG of 10. If we choose to allocate enough MSPs to increase that to 20, for instance, we use an amount of MSPs to double the AG stat and thus improve the to-hit value with a method independent of speed, but is there a better choice?
Another factor is retargeting when the designated target is taken out, so you want onbord sensors which sacrifice either warhead or engines/fuel. Another factor is making sure the enemy can't hit your missiles, so that is space into missile ECM. If it does get hit, you don't want it to die so you need to armor it. You see where this is going? It isn't about 1 is the best, its about tradeoffs. While having a generic missile is a very good idea, it lacks the specialized performance these other types of missiles get.
Every subsequent commitment of the same amount of MSPs suffers from the law of diminishing returns, decreasing the benefit we gain overall. Going from 11 to 12 only nets us a gain of about 9%, rather than the 10% we got the first time, and so on until the increase from 19 to 20 is only gaining us ~5%, about half the benefit of that first commitment. Thus, setting AG to 11 is an "optimal" design choice, because it gains us the highest possible increase in overall to-hit, for the lowest investment of MSPs..
Engines also suffer from diminishing returns while you don't see it unless you go crazy at mid level techs, as you start advancing into really powerful engines, you notice it quite a lot. It gets to the point where even the "optimal" percentage of engine to missile starts becoming sub-optimal compared to other designs.
Ideally, yes. If the first time you meet a given race is when their war fleet drops into Sol or a system one jump away or something, you might want some ordnance on hand though. So having some missiles would be better than having none. And having missiles that are more likely to be at least somewhat effective is generally better than having missiles specifically designed for the wrong target
However, you can also design differing generic types of ASMs, like Long range that sacrifices speed/warhead for a bit more fuel, or short range that sacrifices its fuel for more speed/warhead. Etc. There is more than one type of "generic missile". My generic ASMs always have some onbord sensors so they can retarget while inflight as to not waste resources.
Title: Re: I think I create too slow missiles
Post by: Iranon on October 27, 2016, 11:09:07 AM
@ Tall Troll: You're misapplying the concept of diminishing return. Your optimum can be at a point far beyond the spot where diminishing returns kick in.

If Manoever Rating was tracked to 2 significant figures rather than integers only, you'd presumably argue for enough agility for a MR of 10.01, satisfying your "maximum gain per agility point spent". That reasoning would be more conistently applied by assigning no agility at all.
MR 10 or 11 is terrible for a general purpose missile, whether we know specifics or not. The only thing it's good for is as a dedicated decoy to run the opponent out of AMMs - hard to shoot down, we don't care that accuracy is terrible because they aren't expected to reach them (when the opponent has run dry, we switch to missiles that can actually hit).

*

If we are afraid that we may fail to penetrate the point defence screen at all or that our missiles may not catch a fleeing opponentl, speed > accuracy.
If we expect that few missiles will be engaged, let alone shot down (thousands of simultaneous missiles, or hundreds split into one-missile salvos), accuracy > speed.

With enough details, we could work out the optimal split between engine and agility.
If we fire one salvo of 100 missiles at a target that has 60 CIWS shots tracking at 20000km/s, expected damage is proportional to 100*accuracy - 60*0,5*20000/speed.
Assuming our missiles have a speed of at least 20000km/s, that is.

In most realistic scenarios where the missile strike isn't borderline pointless, a reasonable amount of agility will perform better.
Title: Re: I think I create too slow missiles
Post by: GetStqned on October 30, 2016, 04:45:06 AM
If you want to be effective , why not specialize missile ? One for heavy enemy ship , one for lighter , for fighter , for fast or low speed , it will be more costly in resources and money but you will theoretically invinsible not?
Title: Re: I think I create too slow missiles
Post by: Garfunkel on October 30, 2016, 07:38:11 PM
Remember that you cannot carry endless numbers of missiles with you. The more types you have, the bigger the risk that you will run out of effective missiles at a critical moment.
Title: Re: I think I create too slow missiles
Post by: Iranon on October 30, 2016, 08:07:16 PM
If you field specialised missiles with varying capability, it may become problematic to concentrate missile fire to overwhelm enemy defences.
If you field missiles of varying sizes, logistics may become an issue, especially if you run dry on a smaller type and your ships can't fire any ordnance that is on hand.

Sometimes I create variants of identical size and speed though, say a long-ranged variant for ships and a short-ranged variant for fighters that devotes more space to warhead or agility.