It's an exploit. Would conquerors be able to just step right in and use another faction's 'homeland' or 'military cleruchy' governments? Possibly they could to use someone's 'allied state' govt, but then those are cheap and quick anyway. There are only so many building complexes in the game, and we can't force more to work than do (64), so we try to destroy them 99% and tell you that you should build your own, but if someone likes playing EB but doesn't like the idea of a new people needing to set up *their own* types of government, then I guess we've failed.