Hot take, be warned:
ROC (Taiwan) and PRC vehicles sharing a common China TT is problematic for tech tree identity and matchmaking.
To put it mildly, the two are politically “not on good terms”, and have vastly different policies, military planning, and equipment.
This is especially a problem in simulator battles, which aims to pit “western” and “eastern” tanks against each other. Since ROC shares TT and matchmaker with PRC you’ll have M41, M48, M60, F-16 etc. on both teams. This complicates IFF (Identify Friend or Foe) and ruins the spirit of the mode.
You also have problems like the one you mentioned, where some players resent high tier US equipment going to China TT, where it will benefit a playerbase and lineup mostly consisting of PRC equipment. IRL ROC procuring Abrams is meant to assist USA in potential conflict with PRC, wheras in game it is the reverse.
This is why I think combining post 1949 ROC and PRC in the same TT was less than optimal. IMO it would be better if all ROC vehicles in China TT were replaced by North Korean ones.
The removed ROC vehicles could then form a new TT together with South Korea, with possibly other asian nations joining them. This avoids the issue of Japan, since ROC and Korea don’t have nearly as problematic of a history/relations.
Joining ROC together with SK also boosts the amount of unique vehicles and increases lineup potential for mid and lower tiers. They would also participate in the appropriate team in Simulator battles.
Maybe it is too late for such a drastic change, but I believe it would be for the better if this was done.
TLDR: Fewer people would complain about modern Taiwan (ROC) equipment if they were seperated from PRC Tech Tree.
Edit: Maybe call the tree “Four Dragons”, and include Singapore & Hong Kong as well. Four Asian Tigers - Wikipedia