Your math is suspect, one, and two, even if it were to check out, we're talking about production stemming from the PP. Something that Sid has needed less of to score points over his career vs Ovechkin. Fact.
You suspect Malkin has never assisted or scored the goal on more than 30% of Crosby's points in a given season? Perhaps by not knowing this, you are unintentionally misrepresenting the team factor in their points.
I was curious about this, so I went stat-hunting. However before I post a huge wall of text, I'm curious what percentages people might ascribe to those numbers. For what it is worth, Crosby has 730 even strength points, 424 power play points and 8 short-handed points. Malkin has 591 even strength, 374 power play and 5 short-handed points. They have connected on 1 goal short-handed, Crosby from Malkin. So of Sid's 730 EV points, how many does Malkin have a point on? This includes Crosby goals assisted by Malkin, Malkin goals assisted by Crosby, and other player goals assisted by both Crosby and Malkin. Similarly, what is the percentage on power play points?
For the sake of comparison, I compiled Ovechkin and Backstrom as well, and people are welcome to guess at their percentages too. For a baseline, Ovechkin has 395+318=713 even strength points, 237+212=449 power play points, and 4+1 short-handed points. Backstrom has 148+345=493 even strength points, 69+278=347 power play points, and 2+0 short-handed points. Ovechkin and Backstrom have never connected for any short-handed points.
There's no point in asking for Malkin or Backstrom percentages separately, by the way, because the numerator would remain the same while the denominator would just get smaller. I'm also not trying to use this as a proxy to argue that Crosby and Malkin play together more than people think, because most of their EV point sharing is from earlier in their careers.