Semantics
PUBLIC ENEMY #1
you can score a lot on weak teams but buffalos team is ass they're not the islanders, only one other player is likely going to finish with more then 5o points on that team.... you can also score a lot on a deep team, especially when you dont draw the hardest match ups ala marner, should be something like A versus B+(big of guess but should be close to what it actually is) going by zekes grading of qoc.
that and the nature of playing center is much harder then playing wing, i would say they're is still a sizable gap.
On a weak team like Buffalo you get more score effects and garbage time in your favor (opponents get a lead, then sit back). You also get more ice time and a monopoly on PP time, zone starts, and other offensive opportunities.
On a deep team like Toronto you get the opposite of the above (e.g. Matthews/Bozak lines rack up a few goals and the team stops pressing offensively), but you get better linemates and better matchups.
It's a wash. Good players will produce in either situation, see McDavid last year vs this year, guys like Gaudreau, Tavares, etc. producing on bad teams. Kessel produced about the same on some horrible Leafs teams as he has on the Stanley Cup champions.
Apart from that, Marner's ice time is abnormally and extremely low for a player of that stature even for being on a good team. Laine is the only other player I know of whose ice time is so out of whack with their offensive success.