I agree that the pitchers staying healthy is a big if. I don't agree that the offense rebounding is a big if. I think the latter is rather likely, actually.
As far as the Yankees 7 game advantage and the addition of Stanton, Fangraphs still has them projected for 91 wins, just like the Red Sox. And the 2nd of my favorite three go to projection systems, Clay Davenport, currently has the Red Sox winning the division over the Yankees by one game. (The 3rd of my favorite three, Baseball Prospectus, is not out yet.)
I understand that you take projections with a grain of salt, but on paper, we are currently as good as the Yankees.