Two points to throw out for consideration.

First, if you are going to conduct a census why not ask some pertinent questions like "Where do you feel the authority to rule comes from?" This might give you and idea of the type of government that the people will listen to based how what they feel is the source of legitimacy. I can expand, but not without more space.

Second. It really does not matter what their history is initially. Hell, you can create their history for them. What matters is what they need out of a government. That is what you need to determine. It might be that they need a connection, to feel like they are part of something, in which case you may have to recreate what was. But it may also be that they are simply looking to survive.