Better dominance? The difference between the YE # 1 is literally a good end to last season for Djoker and and injury which means Rafa could play out the rest of the season. That is the difference between the YE # 1 numbers being reversed. Ditto with the weeks, you give Nadal YE # 1 last year and he adds all the weeks from the offseason right through to the AO and the gap is much closer. So yes, whilst Djoker leads, it is hardly a gaping hole.
Distribution is a myth - a slam is a slam. A masters is a masters. Djoker has won 8 clay masters, Rafa 9 hard masters. Djoker has won 10 of his 15 majors on hard, Rafa has won 11 of 17 on clay. It doesn't matter though, a slam is a slam. Rafa has won at least twice on each slam surface, Djoker has not yet.
And finally, Djoker is behind in the slam count, so I'll have to respectfully disagree on the premise of the thread.