Spain would be not bad
The factions could be Castille, Leon, Portugal, Aragon, Catalonia, the Emirate of Granada and the Almohades in Morocco. Perhaps the Kingdoms of Mali and Ghana too.
I would also like to see an expansion of the Americas. You could go south and see the Incas or North and focus on each individual region. The Delaware, Iroquios, Huron to the East with France and England. To the North West would be the Aluets, Tlinget and Haida along with Russia and the Inuit. Then you would have the Nez Perce, Sioux, Crow, Pawnee along the plateau and the plains. The South west would have the Apaches, Pueblo aliance and the Navajo. Portugal, the Dutch and Germans could also be involved.
Another two ideas I have are
1. The fall of Byzantium- The factions would be Byzantium, the Seljuk Turks, Hungary, Venetian empire, Golden horde, the Kipchaks, Bulgars
2. The expansion of the Ottomans/ fall of the Eastern Europe- The factions would be the Ottoman Empire, Timurids, Hungary, Serbia, Wallachia, Holy Roman Empire, Poland and the Bulgars.
The Teutonic campaign should have the Kingdom of Sweden, and the Finns too.
In war wolves are smarter than men. We Mongols learned from them how to hunt, how to encircle, even how to fight a war. There are no wolf packs where you Chinese live, so you haven't learnt how to fight a war. You can't win a war just because you have lots of land and people. No, it depends on whether you're a wolf or a sheep.[This message has been edited by bloodswan (edited 04-04-2007 @ 04:29 AM).]