Well damn. It appears that I wont be using Backdoor Hacker.... Ever. Unless someone can figure out how to defend 2 HWs from +5 City FS Exos, Botnet Hard, Golem Hard, Spirecraft Hard, all at the same time. I REALLY wish we could build a city on the HW, THAT might actually have the strength to hold it off. Hey Keith maybe a small change to allow that? Or would it be too much cheese?
I can't tell whether you're joking, but... Of all the nearly infinite possible ways you can set up this game, you've picked an extreme setup that maximises exo strength, one no-one would recommend as a balanced game. Then you've combined that setup with the one particular AI out of the ~64 on offer that leaves you particularly vulnerable to exos. With a game that offers such tremendous potential for customisation, it will always be possible to create scenarios that aren't winable. We can't expect the devs to balance for every imaginable combination of minor factions / AI types / homeworld numbers / AI plots / map type etc.
Actually not joking. My standard game is 2 HWs, with 8/8 using Insert AI Type/Bouncer & Insert AI Type/Bouncer. I have Botnet, Golems, Spirecraft, and FS all turned on, set somewhere between 4/10 - 6/10. I do that because in a FS game, once you get at least 1 Spire City up as a choke point normal waves, even CPAs, are mostly meaningless. All you do is clear out the threatfleet from time to time, and nothing else matters. Exos are the only thing that is a meaningful threat. I'm not saying that Backdoor Hacker is, or even should be, balanced in such a setup. I am saying its an AI type I wont play with, BECAUSE it cant be balanced against how I want to play the game. The point of my questions were to find out if the exos will strike from the backdoor. It turns out they do. Should they? In all honesty, yes. But this makes it unsuitable for my playstyle. This IS NOT A PROBLEM. As you pointed out, the shear number of other possibilities gives me more than enough to play with, so having a few AI types that don't fit is something I don't notice.
Now, as for my suggestion about Spire Cities being allowed on the HW, well I can't decide if it would be pure cheese or pure awesome. On the one hand, with the station unlocks giving it both planetary tachyon, a gravity field with disables enemy teleportation, 100% damage boost to everything you have, and 2 stations worth of guns, the homeworld(s) have serious defensive power already. On the other hand, all of the stations damage output is reduced by a drastic 75%, and Fallen Spire Exos can be REALLY crazy. With the insane durability of starships, and the even crazier durability of golems, those guns aren't going to do much of anything reduced as they are. Their secondary utility, knockback, is ignored entirely by all golems, H/Ks, and even most starships. (Rather glad that among the few starships it does effect is the damn raider. No more "Single AI Raid Starship kills me" losses) A Spire City, built for pure defense, adds 6 shields, (which do NOT reduce damage) 12 heavy slots and 24 smaller slots. Suddenly turning the human HW into a veritable fortress, like the AI HWs, is rather do able, even against heavy exo forces. Should it be allowed? I'm honestly not sure. Yes it can be stupidly strong, but unless youre cheesing in the lobby, then the response from having FS benefits is also incredibly powerful as well. It only grows in power as the benefits from the FS do, as well as increasing with time.