The difference between Gretz, Orr, Mario, etc. is that McD was a victim of a franchise that had no idea what the hell they were doing at the time and did a bang-up job of getting top picks, throwing them to the wolves with very limited development and running the whole show into the ground for damn near a decade.
When the Oilers got its collective head out of the rear, everything got better and McD, at 26, is now developing into the player he should have been at 21-22 on any other roster.
It's really easy to say pure talent is everything, but for players like the ones above, their talent was developed, honed and through the hands of solid coaching and talented teammates and vets, weaponized.
The Oilers of the decade he was picked from the draft was far worse and horribly ran than most teams save Buffalo before their turnaround.
I say give him 5 years and see where he's at then. He got robbed out of quite abit of time and development and in threads like this, it haunts him and his name.