To further put Lemieux's highest PPG season in context, I do not believe for a second that he would have maintained the 2.66 PPG for 80+ games (just as Gretzky did not maintain 3.0 PPG after the 51-game mark).
Pittsburgh finished 1992-93 with a 17-game winning streak (and a tie in the last game), which obviously would have been a high-PPG period for Mario (for example, he scored 5 goals against NYR on April 9th, 1993). But that would not continue for 24 more games (indeed, after 17 wins a row, they went 3-4-1 in the next 8 to be eliminated).
Had he played 84 games, I expect Lemieux would have ended up around 2.5 PPG. However, even if he had stayed at 2.66 (and he wouldn't have), he still rests at 3rd-best, and that in the easiest season ever to score big points.