It has been a long time since I played or modded Hegemony gold to any serious degree but I recall that there was no such thing as a 'rebel' faction.
From my understanding each settlement needs to belong to someone. Therefore, it would be possible to give away all the starting cities of a single faction that you wanted to play to a neighbour but there is no way to make the open sandbox where everyone has a single city and they need to conquer from rebels.
No doubt a developer could correct me but this is what I believe to be true.
EDIT: On second thought, it may be possible to create a new 'rebel' faction and give them every single city except for the capitals. Would make them hugely powerful but since the AI is so passive in Hegemony Gold they wouldn't go around conquering. On the other hand, the single leftover cities wouldn't do anything either so it would just be more boring doing it that way.