Please consider these suggestions as your remaining factions:

1. The Teutonic order. Script them as an emerging 'horde' in the 1100's. I hear the 'horde' type of faction as been reintroduced as in BI. Historically they started in Jerusalem before moving to Hungary and finaly to Prussia where they created a large independant state.

2. The Knight's Hospitaler. Just like my idea for the Teutons. Granted land in Cyprus then Rhodes then Malta all the while fighting against the Mamlukes and Turks as an important naval power, they even fought against the Timurids.

3. Persia. Just as you have split the other islamic factions in three ( a great idea ) so can you do with this one. Khwarazm-Ilkhans-Timurids. The Khwarazmians fled to the middle east after the destruction of their state ( another horde-faction?) allied themselves with muslim rulers there, and after being defeated fled back to the mongols. The ilkhans and timurids had a lot of persian influence and i think deserve to be put in as the mongols were not unified and conflict existed between the golden horde, ilkhans and timurids. A 'Persian' faction which starts out as a muslim culture and ends up more mongol-persian later in the game would be a great addition.

4. Sweden

5. Another Russian principality....please

I'm not good with computers but offer to do some historical reasearch