You won't necessarily get troops on the ground without losses. The troop ships will be engaged on the way in and in orbit. You have to end the increment before the drop in orbit, so short-range defences will engage them. Also, you probably take fire during the approach to the planet, so troops could easily be lost in the bays.
There is nothing to prevent building a large carrier that stands off from the planet and dispatches smaller ships to make the actual drop, although if you want to do that with larger formations you will need to split them and recombine on landing. However, I suspect that large, well-armoured ships will be the best option because of the benefits of large size on armour protection. Plus you can also send in escorts to engage the defences or missiles to keep any point defence occupied. In fact, with a large enough armada, you might even get boarding ships close enough to launch against orbital bases.
Steve, can you at least try to implement large formations being loaded onto multiple ships at least as long as they are in the same fleet? Having to do extensive recombinations seems awkward, and the viability of small landing craft should live or die with their survivability, not the patience to restructure units.
I really don't want to go down that route due to potential complexities. Given the large differences in sizes of different units (5 tons to 500+ tons) and the possible combinations of different landing craft sizes in the main fleet, the code would need to figure out the best way to load them all, then keep track of the split (using a new type of sub-formation) and display that on the UI. Plus what happens if the fleet splits (either voluntarily or due to damage)? Do those sub-formations in the split-off fleets become new formations?
One of the goals with C# Aurora is to make large ships more viable and I think this area is one where large ships will actually have an advantage. For example, here are three designs using tech from my current NPR (my very off-the-cuff designs).
This is a very simple military-engined landing craft with 400 tons of capacity and 24 points of armour
Landing Craft Small class Troop Transport 955 tons 29 Crew 159 BP TCS 19 TH 128 EM 0
6701 km/s Armour 3-8 Shields 0-0 HTK 4 Sensors 0/0/0/0 DCR 0 PPV 0
Maint Life 0 Years MSP 0 AFR 190% IFR 2.7% 1YR 25 5YR 376 Max Repair 32 MSP
Troop Capacity 400 tons Drop Capable
Commander Control Rating 1 BRG
Intended Deployment Time: 3 months Morale Check Required
Magneto-plasma Drive EP64 (2) Power 128 Fuel Use 885.44% Signature 64 Explosion 20%
Fuel Capacity 50,000 Litres Range 1.1 billion km (44 hours at full power)
Another military-engined ship. This carries 12x more troops, has 6x more armour (152) and costs 4.5x more.
Landing Craft class Troop Transport 8,826 tons 79 Crew 707.2 BP TCS 177 TH 544 EM 0
3081 km/s Armour 4-38 Shields 0-0 HTK 27 Sensors 0/0/0/0 DCR 2 PPV 0
Maint Life 0.18 Years MSP 100 AFR 312% IFR 4.3% 1YR 549 5YR 8,231 Max Repair 200 MSP
Troop Capacity 5,000 tons Drop Capable
Commander Control Rating 1 BRG
Intended Deployment Time: 3 months Morale Check Required
Magneto-plasma Drive EP272 (2) Power 544 Fuel Use 53.69% Signature 272 Explosion 10%
Fuel Capacity 100,000 Litres Range 3.8 billion km (14 days at full power)
Finally, a large commercial-engined ship (which needs no maintenance and can be built in commercial shipyards), which carries 125x more troops than the small ship and 10x more than the medium. It has 3390 armour (which is 140x more than the small ship and 22x more than the medium). It could theoretically take 200 hits at point-blank range from 25cm lasers (assuming even distribution). It costs 44x the small and 10x the medium. Plus, every small or medium ship lost means troops lost as well, whereas you have to penetrate all the armour on the large ship before any troops are lost.
Haruna II class Troop Transport 127,890 tons 726 Crew 7,003.6 BP TCS 2,558 TH 6,144 EM 0
2402 km/s Armour 15-226 Shields 0-0 HTK 296 Sensors 8/8/0/0 DCR 1 PPV 0
MSP 34 Max Repair 200 MSP
Troop Capacity 50,000 tons Drop Capable Cargo Shuttle Multiplier 2
Commander Control Rating 1 BRG
Intended Deployment Time: 3 months
Commercial Magneto-plasma Drive EP256 (24) Power 6144 Fuel Use 3.54% Signature 256 Explosion 4%
Fuel Capacity 350,000 Litres Range 13.9 billion km (67 days at full power)
CIWS-160 (2x2) Range 1000 km TS: 16,000 km/s ROF 5 Base 50% to hit
Thermal Sensor TH1-8 (1) Sensitivity 8 Detect Sig Strength 1000: 22.4m km
EM Sensor EM1-8 (1) Sensitivity 8 Detect Sig Strength 1000: 22.4m km
A small, fast ship would be harder to hit for the large lasers (although not for the point defences), although any hit may be fatal and it is unlikely to be so much harder to hit that it compensates for the difference in overall armour and the incremental losses.
Mesons would be a problem for the large. In fact, TBH mesons are so dangerous in general I am considering either making them ruins-only or adding some restrictions (cue new thread
)
Anyway, my point is that small ships are unlikely to have any major advantages over large ships (probably the reverse) once you take the comparative capacity, protection and cost into consideration, so I don't want to spend a lot of time coding something that probably isn't a good idea anyway.