Hope you're right but I think, as far as talent goes, you're off base.
2 of the 4 starting D-linemen last year were NFL draft picks in Branch and Thompson. In addition Rennie Moore, who likely will make an NFL camp is gone so 75% of the D line will be new with only Malliciah Goodman having seen substantial playing time. Coty Sensabaugh, the other player we lose, was also an NFL draft pick. He'll be replaced by Breeland or Robinson both talented players. So of the 4 players we lost on Defense, 3 were NFL draft picks and all four will likely be on camp rosters.
If our starting LB's are the same this year we are in trouble there as well. The 5*'s from 2 years ago should step in this year but if they don't, that's a mediocre unit. All in all the secondary is solid, but the safeties were far too undisciplined last year.
Most of last year's problem was scheme. We had and NFL style defense and when we played a pro-style offense we were typically successful. However when we played offenses that utilized the QB in the running game and utilized a lot of misdirection we were lost schematically. Hopefully the new DC (from oklahoma) will be more accustomed to dealing with spread offenses but there's going to be a learning curve, so between the decimated d-line, the questionable LB core and a new scheme to learn, i wouldn't expect much improvement from this unit until late in the year.
Better hope the offense can carry us until then.