There should be an Alan unit, as they still were kicking around pretty strongly at this time. I think they were Christian. Also, the Khazars recruited many Muslim mercanaries from Khawarzim.

Magyars, Bulgars and possibely Khazars should be able to recruit Slavic infantry as auxalries.
What time does the game start? The Pechnegs could be included, though I think they're too late...