Idk I think having NJoA / NJPW separated may work for the game better, because NJoA is realistically more likely to hire USA workers and it may be hard for the AI to handle that because all their new signings will just be guys from Japan, and plus NJoA have workers that have never worked in Japan before
and AEW / ROH may share the same workers especially low-card workers, but they still run like two different companies. Having a guy like Cesaro being loaned to ROH, rather than having him branded their just makes more sense