'It's not as gauche a question as "which air force would win if EVERY fighter met in the middle and shot it out."'
Forgive me if I suggested it was.
But I believe studies on both sides have examined what would likely occur should a small number of F 22's or F 35's face a far less capable but numerically superior (by a factor of ten or so) force in, say, the Taiwan Straits.
I'll let you guess the outcome.