Instead of portraying those two as one-trick ponies and Roger as the one, the only real magician, you mean?
The clay courts of Roland Garros have been made faster. You could also wonder if Roger, with his preference of faster surfaces with a low bounce, would have been as succesful in the 80s compared with his actual achievements in RG.
This is a line of thinking that can go both ways.
By focusing your argument on "Nole and Rafito", I feel that you're dragging the debate from one tardish extreme to the other.
What the are you talking about? you have to be blind not to see the diffrence between Federer's game on caly versus hardcourt.
Hamburg was the slowest major clay event on tour, and yet Fed won 4 titles on it. He bagled Kuerten there in 2002 and Nadull in 2007.