Haven't seen any Fari Lancers anywhere (there's bodyguard units though). Maybe I don't have anywhere that's high level enough yet? I'd think Kayseri should be, but all I can build are Fari Archer cav, Turkoman cav and Turkish horse archers, which are all pretty decent but don't deal that much damage to tougher units. And yes, the Fari archers are pretty good, but the infantry doesn't hold up against Scoutatoi/Kastrophylakes/Athanatoi (Scoutatoi have 200 units to 123 Foot fari lancers and seem to have better stats too, I'd have to check) and I'm taking horrific losses trying to take settlements (not even to tower fire or oil). I don't really mind if designed as such and it is a nice challenge, just feels kind of lame that I can get better units with the Heitareia barracks in Sis than anywhere else in my empire.
I like the roster. Maybe it's just my experience or just the Byzantine units.