If the offense can move the ball as well as they did in preseason (big IF) then there will be times when the Bills have a big lead on other teams and will force teams to become one dimensional. If that happens, then this defense is going to look better than they did last year. And they will become a turnover generating machine.
If the offense doesn't move the ball well and doesn't score, then I think this defense will look a little worse than last year. I just don't see how its possible to get that kind of performance out of your d-line starters in back to back years.
I didn't think the defense would get better under Schwartz though, and it did. So, maybe this year will be even better. I would be pleasantly surprised if it turns out that way.