Currently, the MTW2 engine of the campaign selection panel can not handle all old+new factions at the same time.
So I need to examine if I put Volga-Bulghar, Seljuks of Kerman and Vladimir at the front campaign panel and put other factions instead (like Ghaznavid, Paramara Rajput and Kypchaks for exemple).
You have right to three choices.
These 8 factions are the 8 most probable concerned.
If factions you wanted nominate are not listed, please, let a comment.