...But 1 fluke GS < 10 weeks at #1. It just depends on how you look at it. IMO you have to be more well-rounded for #1 where as you have to play 2 good fluke weeks for a GS. There are far more fluke GS champs then there are fluke #1's.
Actually it's far easier to fluke a #1 ranking than a Slam. In order to win a Slam, you have to win seven best of five matches against the best players in the world, you can't BS your way.
Meanwhile, the ATP ranking system isn't very different from the WTA one that generated some truly abhorrent #1s. You can easily be #1 without being the best player in the world as it is far from an objective/reliable measure; you can't BS your way to a Slam title though.