Most of Fed's slams were not against Nadal. Nadal has beaten Fed most of the times he played and won quite a few slams against Federer. Between Fed and Nadal - the record books will show their head-to-head as that Nadal is the greater player. Federer was terrific against all others - and was in a weak era before Nadal came on the scene too. Federer will go down as one of the greatest players - who was never able to beat his main rival - Nadal.
What I say now, and many people said, I am sure, before, will never register with you, bet let's try.
Most of the wins against Federer Nadal has are on clay. Without it the head to head would be much closer.
Basically, following your logic, if Fed was slightly worse on clay (let say Sampras, Agassi or Becker like) and did not meet in the clay finals with Nadal, he would be better player because his had to head with Nadal was better?
You forget as well that Fed in his prime could not notch up more wins against young Nadal because Nadal was never good enough to get to the finals to face Federer.
Federer rarely (never?) lost to random nobodies outside top 100 like Nadal did in his last 3 Wimbies between ages 25 and 28.
His one comparable loss was to Stakhovsky last year when he was 32.
Nodal has 5 GSs outside clay, worse than Becker, Edberg and Agassi.
Nadal never won WTF i.e. matches between 8 best players in a given season. This is pathetic.
Many others like Fed, Sampras, Lendl, Djokovic won it many times and clay courters like Kuerten won as well.
You claim that Nadal is greater player than Federer is straight from Nadal fan-boys club cut out book.
Greatness is about more than titles, it is about style, range of shot making, being consistent across all surfaces.
And final point: If Fed was left handed he would be still great player. Nadal playing his style right handed would had not much success apart from clay court titles.
I am not saying that Nadal can not match Roger record of GSs by winning more RGs.
But it still makes him who he is already: best ever clay courter with extras.