When comparing the big 3 in tennis (and IMO):
Roger is just the most naturally talented of the 3, with the most varied game which is in constant evolution - throughout a match, let alone year or career. In rugby terms, he'd be Dan Carter
Rafa is the most naturally gifted physical specimen - the man's an absolute beast, and it's a miracle his knees have lasted this long, but they have, and he's been able to subdue all opposition. In rugby terms he'd be (a better version of) James Haskell
Novak is the most well drilled, trained professional - he's just a machine who never stops grinding you down. In rugby terms, he's be Jonny Wilkinson
You are making Nadal, a 20 grand slam winner, look a bit like a brute. Don't have the stats at hand, but isn't he the youngest ever to achieve a grand slam?
He's is strong, sure, and he is clearly not as elegant as Roger F, but don't let that blur his finesse.
I like Roger's style better, but dear god Nadal has shut up everyone. Again and again. First, he was a one-trick pony. A dirt specialist they called him. Then that he got lucky. Then that he needed to learn to play other surfaces. Then that he's ok on grass. Then that he's good but he'll never beat Roger at WBD. Then he beats the best ever, on Roger's best surface, at the biggest setting in arguably the best tennis game ever played. He wins all 4 grand slams. He's won an olympic gold medal on singles. He's won an olympic gold medal on doubles. He's been instrumental for Spain winning the Davis cup. He has a positive record against his #1 rival, who many consider the best ever.
I really don't see what more he can do. Again, i like Roger better, but resume-wise, there is a strong argument to be made in order to call Nadal the best ever. He has achieved, literally, everything (relevant, course), a tennis player can. Roger hasn't, Novak hasn't either.
Haskell? Seriously? That's like putting a tutu on a pig and calling it Natalia Makarova.