Okay, granted, more generalised governments probably won't fit that well, and are probably better just being there for flavour or the minor races if they ever come into it.
But with species like the Cardassians and Romulans revolutions are pretty often, so they should definitely not be limited in their governments, although you might want to make them a bit more specialised but not greatly different. One thing you could do is make a "Reman Star Empire" that allows you to build a wonder that occasionally spawns the huge Reman flagship from Nemesis, but have the actual government style significantly flawed, so the only way for a Romulan player to get their hands on the great warship is to have the Remans take over and cripple the Romulan economy for a while
But with species like the Cardassians and Romulans revolutions are pretty often, so they should definitely not be limited in their governments, although you might want to make them a bit more specialised but not greatly different. One thing you could do is make a "Reman Star Empire" that allows you to build a wonder that occasionally spawns the huge Reman flagship from Nemesis, but have the actual government style significantly flawed, so the only way for a Romulan player to get their hands on the great warship is to have the Remans take over and cripple the Romulan economy for a while
