It would be interesting to hear more details of what you have in mind. In reference to the OP, will it be possible to change your Pritanoi, Sweboz or whatnot into a kind of polity that could plausibly expand into a far-reaching empire?
On a more historical note, is such political changes at all plausible for the time period? Could the tribal factions have turned into more permanent states with greater military and technological sophistication in the time period, assuming good leadership and an otherwise favourable situation?
Bookmarks