I just want to say that
We could always do a Warhammer IH, with the Elector Counts.. There's at least 10 principalities (Reikland, Stirland, Averland, Wissenland, Talabecland, Hochland, Ostermark, Nordland, Ostland, Middenland), and there's 13 provinces if you count the ones lost before Storm of Chaos era (Westerland, Solland, Drakwald), and 15 if you count Sylvania and the Moot.
But otherwise I support the Alessian idea, and would be a mod. I do recall that you suggested on skype that we setup mod jurisdiction based on the provinces, that could work.