Unheralded interior line? Sure. But All-American/pro starter ends, corners, linebackers, and strong safeties. The defense gets elite players because they analyze the recruits and choose them carefully.
What the offense does has 0 to do with the strength of the defensive personnel.
If the offensive staff took skilled player recruiting and development as seriously as the entire defensive staff does, Iowa would be an elite team. Unfortunately, the Ferentzes are lineman guys at heart, and they don't believe that talent matters as much as hard work and pure size. It shows up in recruiting, it shows up in who plays first, and it shows up in W/L.
The Jimmy's and Joe's matter in college football. They don't in the pros because the overall talent level is nearly equal by design. Ferentz would be a really great NFL coach. Probably Superbowl winning level. But he's just not the dynamic recruiter you need to be to be an elite college coach.