My guess is that you don't know what the term correlated means, here is the definition
"have a mutual relationship or connection, in which one thing affects or depends on another."
Your assertion is entirely subjective in the sense if that one removes the 5 players and just put in the average NHLer in each year the total impact, ie number of goals per game per team across the league still comes up really short
Now unless one thinks that Mack suddenly got better because AM and McDavid whispered in his ear to do so or they bumped shoulders in the offseason and then dispelled some of their superpowers on Mack......see where it goes?
Scoring goes up or down mostly due to league changes either in rules or style of play and especially the size of the goalie equipment more than any single player or even duos like Wayne and Mario.
It’s all subjective, no matter the way you look at it.
If you think the environment of peewee hockey in Canada produced a 500 point phenom who was then lucky enough for conditions to be just right in the NHL for that dominance to continue, then you’re being foolish.
The main flaw and the easiest to smack down, and the one that no one will attempt to argue against, is that talent discrepancies exist. Groups of talent discrepancies exist, and some groups of players are just better performers than others.
Beginning with the idea that NHL talent should be normalized is the original sin of era adjusted stats.
Outliers exist and sometimes extreme outliers exist. Attempting to normalize these extreme (and rare) outliers is a fools errand.
And it leads to ridiculous arguments where fans are debating seasons 3 or 4 years apart and pointing to gpg discrepancies and claiming that explains anything. It doesn’t explain anything though.
If Matthews scores 70 goals this year, they’ll be someone who argues that because goals are magically up league-wide it’s an equivalent 50 goals season from 2018 or something ridiculous like that.
But that person will never be able to predict next years GPG average, even knowing all of the variables that they’ll use to explain retroactively why gpg were up or down in a previous season.
Because this kind of thing is subjective, if it was objective people could predict next years gpg average. We know the goalie equipment size, we know the rule set, etc we have all the info we claim matters. If it was objective, it would be predictive and not retroactive.
What you’re doing is looking at the end results and then trying to find excuses or reasons for it happening.