Are you saying it's unrealistic that Novak will stay the No. 1 until October?
Wishful thinking. Steve Flink said (at the time when Nadal had 10 slams) that Jack Kramer is greater player than Nadal even though Kramer has 3 slams.
Following your logic, I can say that Sampras's superior slam count over Djokovic has a clear explanation and not something which I would mark Novak down against Sampras. Think about this: Djokovic's 2008 season is better than Sampras's 1998 but Sampras finished 1998 as No. 1 while Novak finished 2008 as No. 3. Djokovic would have more slams than Sampras, hadn't it been for Federer and Nadal.
Wishful thinking. Apart from slams, there are other factors (which means Novak does not have to win the same number of slams as Nadal in order to have better career).
Borg is considered better than Lendl despite Lendl spending more weeks as #1. Why? Because Borg won more slams than Lendl. Unfortunately slams are the #1 criteria taken under consideration. First slams and then weeks as #1. Borg is also considered better than McEnroe and Connors even though they spent more weeks as #1 than the Swede.