All this federation stuff makes me think of the outer system Anarchists in Eclipse Phase. They’re not one polity - It’s thousands of different tiny habs and ships and hollowed out iceballs floating out in the trans-jovian sphere. But they’re all sort of loosely aligned, at least enough that they talk to each other and trade data and some materials, and if anyone from outisde their loose alliance tries to fuck with them it suddenly becomes all for one and one for all.