In terms of game physics/engineering/playability, why are STO weapons systems (including/especially sensors) any different from ship-based systems? I think you should follow your core principle of "if I can put this weapons system on platform x, then why can't I put it on y" very closely.
If I follow through on this the following consistency questions arise:
1) Why shouldn't an active sensor be vehicle mounted (if small) or static (if big)?
2) What's wrong with a response of "too bad - so sad - can't be justified by Aurora physics" when players complain that the range of their active sensor is too short to allow them to acquire and fire when a spaceship does a rapid fly-by? (Something I just thought of - Aurora sensors don't have line-of-sight requirements, so active sensors can still target a spaceship below the horizon/on the other side of the planet.) This was the response for years when people wanted specialized weapons systems to put on fighters (to be clear, that was a neutral observation, not a complaint).
3) Why are ground-based active sensors limited to resolution 1? That would mitigate the range problem a lot for large spaceships.
4) Why aren't ground-based weapons designed exactly the same way naval weapons are designed? (Possibly with some alternative [EDIT] tech tracks [/EDIT] for things like magazines to represent vehicle hauled missiles, although even there a patriot battery looks an awful lot like a box launcher.)
5) Why not simply allow the put a CIWS system in some STO units and "regular" weapons systems in others.
6) Why not allow ground-based missile systems?
I think that where this leads is:
A) The ghost of PDCs comes back as a ground unit. I think that an STO unit should show up as a formation(?) (that can have mobile and/or static elements) - the formation could then be the equivalent of a ship in terms of user interface. Formation might not be right term here - I mean a grouping of elements that isn't necessarily highest in the chain of command. Maybe the STO system becomes HQ-centric - there's a special HQ that acts like a spaceship's bridge, and that's the thing that binds the weapons systems, magazines, and sensors. Essentially, PDCs turn into an HQ.
B) Players use the naval technology/systems development mechanism to design STO systems (sensors, energy weapons, missile launchers, magazines,CIWS). There are probably separate "ground based" tracks for portability and reload efficiency.
C) There might be a "CIWS control truck" that can meld the individual components (sensor+weapon+computer) of a CIWS into a sub-formation that can be attached to any formation (not just an STO formation). Note that this might feed back into changes in how CIWS is considered in ship design.
D) The rules of STO combat follow "regular order"
in all ways. An STO HQ essentially acts as a space system on space system timescales.
E) Active sensors and fire control are probably going to generally be too big to be mobile, so there's going to be a lot of static stuff.
F) This brings up the question of armor for static units, which begins to circle back to PDCs.
G) In terms of the original Aurora concept, that planets are tough nuts to crack, I think the general philosophy should be the same as 19th century coastal forts: the ground is a very stable and tough weapons platform that can be used for area denial.
H) The naval crewing requirements will translate into manpower requirements in the STO units.
I) From a coding/design point of view, this minimizes the amount of big-bang rewrite/introduce a bunch of new set of rules. This is good both because it cuts time-to-release and (probably more importantly) it cuts back on the potential for inconsistency between the two rules sets.
There are probably more, but I can't think of them at the moment....
John