The question is if Mack wins this year, is he a top-x player going forward into next year.
Comparing players from 5,10, 20 years ago and using that as a basis for what a player is this coming October is stupid.
3 years is generous already, because when I think of what a player is today, I don't go that far back.
Also, of those myriad of assists, how many are on the power play?
Does he play a prominent position like centre, defense or goalie?
Is he more important than Hedman, Vasi or Point for those cup runs?
No
He better crush those other players offensively to make up for the positional disparity.
Edit:
Let me illustrate this power play mercenary thing a little more.
Over the last 3 playoffs (the 2 cup wins + this year), Kucherov has played 61 games, Point with 53, and Mackinnon with 56.
Point and Mackinnon have 38 and 34 even strength points in those games played. Kucherov has 44.
That means that while playing a much more demanding role, Point has 6 less even strength points, 6 more even strength goals, while playing 8 less games.
Mackinnon has 10 less even strength points, 5 more even strength goals while playing 24 less games.
Kucherov has become much less of a dominant player for the majority of the games (as power play time is significantly less than power play time) over the years and plays the easiest position in the game - Winger - in terms of on-ice responsibility.
McDavid has played 22 playoff games these 3 years. He has 2 less even strength goals and 16 less even strength points in 39 less games played.
