Seems to me that Byzantium is probably one of the least odd formables here. Sure, the name is ahistorical, but the Megali idea was a thing, and as recently as the treaty of Sevres, Greece was slated to get some decent sized chunks of Turkey.
A lot changed for Greece between the Treaty of Sevres and 1936 though, including several million dead and displaced Greeks who had been living in Anatolia.
That said, I am very happen we have more alt-history options baked into the base game.