the volga bulgars were a minor state and had little impact on history.
the teutonic knights shaped modern europe.
the khanate of transoxania? never heard of it, name one historical ruler of this nation.
Unimportant for the ignorant...perhaps you'd like to go up against Orda Khan?

Volga Bulgar was a prosperous Muslim state on the Volga which recieved its cultural nourishment from the resplendent Abbasid Caliphate. It was a major trading center in Bolgar and had several cities prosperous from trade. Not to mention that they resisted the Kievan Rus instead of crumbling like the Khazars.

Well, look, we don't cater to personal preferences, if u like the Teutonic Knights, good for you, we're not including them. We don't make miracles, we can't crack the faction limit. So stop asking as to add factions on a whim.

Khanate of Transoxiana represents various dynasties which include the Qara-Khanids, the Khwarazmians, the Chagatai Khanate. Most important of all, its rich wealth and prosperity of the region supported powerful states in the past like the Samanids, the Saffirids, etc, etc. Even Timurlane had his capital in that region because it was wealthy. Moreover, Bukhara was an importnat Islamic city and even considered a holy one.