Impression I got is that we won't be designing our own starbases. I liked doing it in Moo3, but in Moo3 starbases were just big, immobile ships, they couldn't do anything that a starship couldn't. The same isn't true for GC1, and probably not GC2. I'm not sure I can see add-a-constructor SB expansion co-existing with design and upgrade SB expansion.
I think the real problem is that CG is extending civ-like offensive/defensive attributes to a situation that I don't think they apply as well. In most military SF I've read, there isn't much of a difference in defensive/offensive combat capabilities. There's stealth/ecm, but that can be as much an advantage to the defender as the aggressor. The real differences between an offensive/defensive ship would be, in my opinion:
1) Supplies: Defensively deployed ships are usually deployed somewhere where they can be readily resupplied. Offensively deployed ships tend to need to take enough supplies with them to last longer. This could mean extra storage aboard the ship itself, or if a fleet is deploying, having a support train hanging back a bit. GC2 has this to a degree in that you can stuff more life support into a ship to get longer range.
2) FTL travel speeds: Defensive ships might need to deploy rapidly, though you'd hardly need your entire home fleet capable of rapid deployment. Offensive ships would be more likely to need rapid deployment. GC2 has this, as you can devote more ship volume to drives to go faster.
3) Mine Laying: While it can be used in offensive situations, you need stealth in order to do so. GC1 had something like this in the Planetary Defenses line of social projects, but it's a social project, not something a ship can do.
4) Repair: Closely tied to supplies, again, a defensively deployed ship can rely more on the system it's deployed in for repair, whereas a deployed ship needs to either deploy with support, or be able to repair itself at least enough to limp home. GC1 didn't have this, and so far GC2 doesn't either, though the idea of repair bay modules so that ships can have higher repair rates would fit in nicely. In order for this to really diferentiate between an offensively designed ship and a defensively designed ship, however, the bonus for being stationed around a planet needs to increase, at least towards the endgame. In GC1, by late game, the bonus to the repair rate for orbiting a system is lost in the noise compared to the bonuses for all the different repair techs. This could also seperate "shock" type attack ships from the main line. The shock ships won't be expected to survive long enough to repair between combats, but the main line needs to be able to repair in order to sustain an offensive.
5) on-station ability: I'm not sure how this would break down, though in my gut I know that at least some ships could be designed differently based on this. A defensive unit has to be ready to go live at almost any time. An offensive unit, on the other hand, usually knows in advance when it will be called upon. Flip side of the coin is that same as supplies and repair, rotating out a quarter of a fleet for maintenance is less costly for a fleet stationed around a friendly planet. I can see ways to simulate this, but I think that they'd add too much complexity to the game.
I'm sure there are other properties that could differentiate a defensive fleet from an offensive one, but the amount of defenses and firepower just aren't it in space combat, as both are important to everything but a phoenix-type ship, and even then, defenses are important if you don't get in a perfect killing blow.
The concept of differentiating between defensive and offensive units made sense in a historical perspective. Offensive units needed mobility, defensive units needed low maintenance costs and the ability to "dig in". However, even the US Army now considers mobility vital for defensive units, really blurring the distinction (both for mobility and maintenance costs). It is still true that it takes infantry to hold ground, but I don't see a parallel there that applies to starships, unless you want to start having marine contingents on board ships.
