I like this. The African civs are a good comparison.
I would also add Malta as an example with their “many tongues”. You can basically cosplay as a different civ and no one seems to have issue with it. If there were more options to invest through cards in something similar for a player that might look to do something like that, that would be welcomed.
The new India card Foreign trading companies could be buffed to this extent.
Here is an old post with a full analysis and some suggestions. As you will see, it is pretty silly how expensive it is to buy units right now. I think they should be more expensive than their vanilla counterparts of course, but not to this extent.