I mentioned this in another thread, but the difference in time of possession is pretty small (29 min/game vs. 25min/game this year). That explains very little of what is going on here. Our offense runs much faster, but they now get first downs and long sustained drives, so the time of possession stays close.
The biggest thing for this defense is getting off the field on third down. We're horrible at it. Memphis was 13 for 20 on third down, and they picked up 2 additional conversions from those stops on fourth down anyway. You can't have your opponents be successfully bailed out on 75% of the times you were actually doing well... (since I'm not counting when they convert on first or second down)