Properly done you already have a wide variety of armor types and traditions. You have Western Europeans (Angevins, Capetians, Spainish), Moorish Muslims, Italian Genoese (Merchants and excellent Crossbowmen), German (HRE) experiments with traditional armour & weapon types, Byzantine classical traditions w/"greek fire", Seljuk calvary, Egyptian Naft, Outremer's turcapoles, etc
Just briefly going over the geographical and historical context you can see the tremendous variety.
Extend the map, or extend the period a little and you also have the Mongols.
I have detailed research on all these groups, so although I don't have the ability to get down and dirty with the modding itself (I guess I could learn), I can help a lot with core concepts and authenticity with arms and armour.