We'll say what we know for sure. He wasn't even close in a Wayne/Mario world. Sure, he finished as high as second once, but he was still 79 points behind Gretzky. So he was close in terms of placement, but not distance to the #1 scorer.
How does he do without them? Hmmm............good question. Still great in my opinion. I think Coffey was teammates with 9 of the top 10 single season scorers in NHL history (both being Wayne and Mario) so that isn't an accident either. It isn't as if Coffey was just a passenger, he was a huge part of perhaps why Gretzky cracked 200 points.
Let's also not forget, Coffey was drafted 6th overall. He had a 102 point season as a junior in his draft year. It wasn't as if he couldn't score then either.
I just can't see a year where it happens. Maybe 1987 like others have mentioned if he plays a full year. Take Gretzky and Mario out of the NHL and you've got a 105ish point top scorer. That's possible. Other years Hawerchuk/Savard (1988) or Yzerman (1989) are scoring too much to ignore. Ditto for Yzerman in 1990.
No, I don't think he wins one. 1995 was his best shot and he was still 12 points off.