Not all PP minutes are created equal. Part of what makes up Ovechkin's total number of minutes on the PP is because he stays out for 1:30 to almost the full 2 minutes. So the difference between the number of minutes Matthews gets on the PP and the number Ovechkin gets comes down to Matthews playing the first 1:05 of the PP then being pulled off, whereas Ovechkin plays 1:30 before being pulled off. Because that's where Matthews' extra hypothetical minutes would come from; he'd be staying on another 30 seconds for each PP, rather than being pulled off at around a minute to 1:15.
So for production to remain constant in more minutes like you're suggesting, you'd first have to prove that Ovechkin's production in the final 40 seconds he stays out there longer than the top unit as it is for the first minute of the PP, when the top unit is out there and still fresh. You can't simply assume that the extra PP minutes consist of a fresh top unit who comes out right at the beginning of the PP. You'd be talking about Matthews getting an extra 20+ seconds at the tail end of the PP, when most of the top unit is already changed and Matthews has already spent over a minute on the ice.
Well if we're going to nitpick like that, how do we account for the disadvantage of PP setups where the entire purpose isn't to just pass the puck to Ovechkin for a one-timer into an empty net?
First off, you're not even really correct. While Ovechkin does stay on more than his peers sometimes for the 2nd unit, the main difference is the additional PPs his team has gotten, and the fact that the
entire 1st unit stays on for a large majority of the available PP time. Outside of the 1st unit, the most a player on their team has played on the PP is 1:14 per game over the last 2 years, and there are only two players over a minute.
I have seen no evidence that extra PP time is detrimental to a player's scoring rate. Players barely move on the PP, especially Ovechkin; they don't need to play the same as an ES shift. What may effect his production is playing with lesser linemates as part of a 2nd unit, but
Matthews did that over half of that sample, so there isn't any comparison. As I said, those numbers actually undervalue Matthews. I'd like to have a bigger sample, but the gap last year when both were on their team's #1 PP unit is gigantic, and most Leaf fans would say last year's PP was pretty dysfunctional at times.
The amount of people blowing a fit because I called Ovechkin a top-5 goal-scorer is ridiculous.