Sub-factions would be cool, so if you join the rebels, for example, you dont have to be a power hungry guy who wants to destroy the world, perhaps there could be characters within each faction you could allign with and to their ideologies.
Sometimes in G3 it is annoying having to be either authoritarian oppressive loyalist or authoritarian oppressive freedom fighters, it's like the choice between facists and communists. Would be nice to have a more moderate option in the form of sub factions.