Always considered Robinson & Fox like Mentzer, but better. Robby's density in particular blew away Mike, who lacked detail, possibly because of his HIT training. Szkalak & Padilla comparable too, but Mike was up there & received tremendous hype, in part because of his innovative training and in part the fact that he was one of the better white bodybuilders then.
Mentzer, Robinson, Padilla & Szkalak all left the IFBB quickly because of politics. If Weider had been fairer and allowed these guys to win as they deserved, the early 80s competitive scene would've been a lot more interesting.