Except for the perhaps slightly inconvenient fact that Jorge actually managed to win 3 world titles over a time period during which Valentino won none.Lorenzo was the same (at least post-Assen 2013).
When everything lined up, he was faster than Rossi. However, his off days were lower than Rossi's. More simply put, his highs were higher but his lows were lower.
None of these guys are infinitely adaptable, and historically maybe only Hailwood and Lawson could ride absolutely anything, and I am obviously not relying on my own observations where Hailwood is concerned.
I suspect MM could ride anything, but everyone including me and probably Valentino himself thought that of Rossi before the Ducati adventure, and even MM was not really prospering on the original tire last season.