How can I make a chariot officer for another faction besides Africans and Brits? They are the only ones that I can get to use the javelin rider stance/animation.

I've tried linking another officer mesh wit javs in the proper weapon bone... no luck. I've also tried entering a new faction's precursor before the "chariot_officer, like "X_chariot_officer, still no luck. How can I get other officers to function the same way as Brit and African? So far I can only get them to function in the standard rider position like scythed chariots