The deep and intensive research is up to LJF. There's only so much that I can do.
I don't think James Tien would hold a grudge against Lee for being demoted. Tien was already a movie star by HK standards, and he would make loads of other movies long after TBB. Regardless, the scenario you provided (Hsu Chien surviving and he and Cheng evenly share the movie bill together) is an interesting one.