Why put so much effort on those history films in campaign? If it’s not immersive to the context set ting up for this game so what for? If it were not because of the history of Eastern Roman Empire, who cares Byzantine civ? Just call a random funny name for the civ and design anything you want without any limitation (who cares and why player vote for it?). I think that’s the point.
Again, Appealing that “Empire of Jade” sounds a joke for a Chinese speaker. Apology for my skin-deep knowledge of history but I’ve never read “Jade of Empire” in any history book. If dev separates those fictional civs into another game brand, I’m good with that.