Seems to me like they're a mix between the Empire from Elder Scrolls and the United Nations from The Expanse (the books), it kind of depends how you look at them as to whether they're 'evil' or not. I guess there's also a bit of Starship Troopers/Roman Empire thrown in there too with the whole "become a soldier, earn your citizenship" stuff.
We don't really know the ideologies of the UC and Freestar Collective yet, so I'm interested to find out if the UC are something like martial authoritarians or a maybe an imperialist democracy. If the Freestar are more like the Rebels from Star Wars I'm siding with them, but if they seem to me like they might be on that usual libertarian I-just-want-my-guns-and-no-taxes schtick I'll side with the UC (or stay neutral).