I'm sure they would have... I just have this idea I feel the need to play with :)

I'll see about putting together a version that just provides Byzantium with my gunpowder units and doesn't change anything else, but they may be just a tad uber for the unmodded game.

Basically I'm providing Byzantium with a Musket Militia (Which, historically would not see it's appearance for a long time yet), their professional Musketeers, a Dragoon unit (Basically Reiter equivalents) and a light cavalry mounted rifle force... basically a logical extension of the Byzantine horse archer tradition.

Those four units would give them a not-insignificant boost in late game power... Possibly making them the strongest faction in the late game. But it's certainly within the realm of what they might have developed had they not been crippled by the events you mention Quillan.