I understand that the personality system needs fleshing out, but I'm not convinced that I'm the guy to do it. I simply haven't played enough AIW to evaluate what ideas would be workable and what wouldn't without any way to test them. I was mostly just putting this out there to see if anyone else thought it was an interesting idea in theory. I do certainly think that if (when?) the moddable version of AI War exists, then I might be able to plausibly develop this a lot further, with the ability to hopefully prototype ideas fairly quickly and see if they work. For example: A super that builds up mini-drones like a Hive Golem, then looks for a planet with some kind of battle (either a wave hitting a human world or a human assault on an AI world, based on whether it's offensive or defensive) to release them before fleeing to AI deep space to rebuild it's forces: is that fun to play against, or just so unpredictable it's annoying? I don't know, and I can't find out until AIW2.
But anyway, I think there almost certainly is a decent number of different, meaningfully distinct things that these could do. For example, it's not a massive leap to go from the aforementioned hive-thing to something that would amount to a Spirecraft Penetrator, but the two would serve nicely different purposes. Also, seeing as most people would be unlikely to crank this all the way to 10, I suspect that even only about 10-15 different types would feel like boundless variety.
However, here is a provisional list of possible personalities that I can think of right now (this is as independent of weapon choice as I could make it):
Special Forces Sargent (just hangs around with the specs and joins in with what they're doing)
Threatener (Acts like threat and joins with AI aggression)
Wave Support (Waits for a biggish wave, then attacks the planet at the same time)
Hit-and-run (Enters a planet with something happening on, does something (drones or sniper fire, probably), and leaves)
Avenger (Lurks on neutralised AI planets, gradually rebuilds defenses and attacks human stuff entering it)
Mobile Eye (Gets a considerable bonus to strength compared to others, but won't engage human forces unless they're overwhelming on an AI planet)
Sieger (Mounts long-range weapons or drones and counter-sniper coverage, sits on the edge of gravity wells and whittles down human defenses)
Transport (Sacrifices raw power for awesome defense and a transport ability. Tries to get AI fleets past defended human border worlds to squishier planets)
Considering I thought of all of those just before going to bed, I think 10-15 shouldn't be too unreachable. Some of the above might suck. But multiply those ideas by all the meaningfully different modules they could potentially have (guns, shields, snipers, spiders, drone bays (with plenty of options for what the drones can wield), tractor beams, orbital mass drivers, ion cannons, reclamation weapons, mini warheads, tackle drones, plasma siege cannons, attrition emitters, mini wrath-lances, munitions/armor/speed boosters, contruction stuff for rebuilding AI planets...the list goes on, probably) and it's already possible that nobody would ever see the exact same set of supers that someone else did. And you're right, having them be specialised is much more interesting than having each one mount roughly the same generalised mish-mash of guns. (Damn, now I can't wait for AIW2 when I can test these out) Thoughts?
Moving back to Astro Trains because they're an interesting topic, I think that you're absolutely right with player agency. I've barely ever played with them on because halfway through the time I tried them I realized that I wasn't able to do anything about them. This is why I think that despite all their flaws, Hybrids are by far the best existing plot. They do both of the things that I believe a plot should do: they make the game objectively harder, but they can be dealt with by the investment of player resources and effort (I believe it is possible to entirely remove them from the game, but correct me if I'm wrong on that bit). Astro trains get the first bit right, but not the second. One possible solution (that just occurred to me and is probably terrible) would be to spawn a finite number of them but increase their health/armor each time one is destroyed. I don't know how this would work with nuke trains and similar, but it would at least allow the player to reduce the threat they pose as the game goes on and they get a bigger fleet (that can thus take out tougher trains) and it would allow for an element of choice in which ones to leave alive and which to destroy. Thoughts?