Nadal and Federer belong to different generations. Federer needed more time to reach the top but once he did, he has been dominating in 3 of 4 Slams in the last years. If he had won his 1st Slam at 15, winning 1 Slam every year he would own 10 Slams at 25 (the same situation).
But itīs also unfair to compare a 20 y.o. to one of the greatest players ever at 25 like some Fed fans usually do.
Nadal has over 5.000 ranking points which would be enough to be a solid no. 1 in a normal situation like Federer admitted. Itīs not necessary to win 10 majors to be an awesome player. I think Federer is making some people lose perspective.