Not consistent enough on clay...
lets see
He won back to back titles at Barcelona at sea level, and won back to back titles at Madrid at altitude. He has won Buenos Aires and Rio.
As far at RG is concerned, made the semis last year, and is in the final this year after only playing three matches before hand. No person who isn't natural on the surface basically skips the entire clay season, and then makes the RG final.
And as far as Wimbledon goes, his quarters and semis were against Rune, and Medvedev who are no grass legends, in fact Rune himself was learning the ways of the grass last year. He was very close to losing the final also, had he lost that second set tie break, he was history, something he admitted.
So, I don't see what you see, so happy for us to disagree on this. I think he is made for clay, and will own RG for years to come.