It is irrelevant to compare Yang and Zhou beyond general relativity because we are not discussing any thing beyond general relativity.

Your admiration of Yang is understandable. However, obviously you are pretty ignorant on Zhou's work. He is the first who understands Einstein's equivalence principle implies invalidity of the covariance principle. This important fact was overlooked by Einstein and others. Therefore, his is the greatest theorists on general relativity of his time since Einstein. On the contrary, Yang does not understand general relativity. His proposal of 1974 was identical to a paper of 1962. Moreover, it has many known defects (please see the references).