This is actually a rather deep draft when it comes to the defensive side. A lot of players who could go in the 2nd or 3rd round are going to drop into the 4th and 5th rounds on the offensive side of the ball. Defense is really deep so I wouldn't be surprised if you see some really good edge rushers or safeties available in the 3rd or 4th round who should have been drafted in the 2nd or 3rd round. I think the weakest is probably LB and TE in this draft.
There could be a lot of players available on the defensive side when it comes to the 3rd or 4th round who could be role starters on the defensive side of things (nickel CB's, pass rushers, etc.). I think teams with extra 3rd and 4th round picks will be surprised with who is available and will be the ones who benefit the most.