But then, wouldn't it be feasible to include the Yuezhi as an emerging faction in the East? I can understand the reluctance to use such a feature anywhere else on the map, since the history leading to a potential emergence is totally different after the first few turns. But the Yuezhi emerging hinges on factors outside the campaign map and anything happening there, and they did play a massive role in the east of the map.

Just my thoughts. I know EB isn't planning to include emerging factions, but in this case I think an exception would be worthwhile. definitely if a number of other possible contenders may as well be portrayed by (assisted) rebels.