It's Absolutely amazing and there is no right and wrong answer in my book. I Think the only thing I can say for definite is that Nadal is the Greatest ever on Clay.
People can say Borg could've done this and that , but these 3 actually did it!
The most amazing thing is that if you add up all their Majors, that is 15 whole years of majors between them ! that is ridiculous when normally a sportsman might be in the top 1 , 2 or 3 for 5-10 years max.
if you held a gun to my head , i would say at the Moment Fed overall, Nadal Clay, but Djokovic will overtake Fed and become GOAT.