If Fields puts up great numbers, like top 10-15 in yards, TDs, completion %, etc., cuts down on the sacs, and the offense scores a lot of points, but the defense cannot stop anyone. Wouldn't people be able to separate that?
I think a more likely outcome is that he's basically the same guy with fewer sacs and more passing yardage. If he still has problems with the swing passes and short-yardage accuracy but is able to hit on long passes and can still get yards with his legs, the Bears are in a tough situation.