There's no indication Toronto's peak is naturally higher than Montreal's. Based on what? Last season started in October 2019, making most of those numbers almost meaningless now. Comparing rosters? Montreal's roster has shifted so substantially that even Habs fans have no idea what the 2021 team really is. I understand the temptation to use old data from outdated rosters to predict which team is better; after all, basing opinions on the current 10-game sample is pretty thin evidence. But the habit of looking backwards to make predictions doesn't work after so much time and so many changes.
That said, Montreal obviously isn't sustaining a 4+ GF/G pace. They don't have to -- they've won every game by 2 goals or more. And of course Toffoli is due to stop scoring at his current pace; at the same time, Danault is due to start scoring... period. Things will equalize, the Habs will regress somewhat (they're currently at an 89-point pace for 56 games) but wherever they finish won't be based on leftover impressions of what the Habs were last year.
As for the Leafs, the Habs can't touch their elite forward talent, but your four stars are already producing at more than a PPG pace -- what higher peak do you think they'll reach? Toronto's defence also looks stronger so far -- do you believe they're due to get even better? Andersen's been erratic, but so has Price for Montreal. Both goalies probably have room to improve. Toronto is currently on an 87-point pace for 56 games -- they'll probably regress, too.