Safin is overrated........comparing a GOAT level player like Nadal to a 2 time Slam winner is a joke
Tsonga, Del Potro, Gonzalez... have one Slam combined yet all beat Nadal in straights at a hardcourt Slam. Davydenko has 0 Slams and has a positive H2H vs Nadal.
Bottom line: no one is debating who is the greater player, there's no discussion there: it's Nadal by miles. The only discussion is whether Safin could beat Nadal at the hardcourt Slams - he doesn't need to own 10+ Slams, or even one for that matter, for that to be a legitimate question.