Okay, given that, Hellebuyck should have stopped 5.2 more goals than he has (0.6% * 867 shots). So the "should have" difference is about, but not quite, 2 points in the standings.
Holding Brossoit to the same standard, he's stopped about 8.2 more goals than he has (2.4% * 342 shots). Almost, but not quite, 3 points in the standings.
So it seems reasonable to conclude that even if we didn't benefit from the "due to Brossoit, in spite of Hellebuyck" factor, that this team is still 1st in the Central and 2nd/3rd in the West.
A visible factor to be sure, but not the nigh Apocalypse or anything.
And given Hellebuyck's horrible start and recent much improved play (.920 in December's 9 games), I'm anticipating this correcting itself as the season continues along.