Agreed, ground BRs should be increased to 13.0. Type 81C would be 12.0, along with Type 90s, Tan-SAM kai could be 12.7 (only if and when they make it work absolutely as it should, that means fixing the bugs and giving it its key features), Type 10 to 12.7 (could be 13.0 if they fixed the armor and mobility issues, absolutely 13.0 if they gave it its 3.5s reload). Honestly the only SPAAs that could be 13.0 would be the IRIS-T SLM and, again if fixed the bugs and given key features, the SPYDER.
I’ve been playing the game for over a year now, air got its BR increased two or three times since I started.