Yeaaaa...I pretty much disagree with your entire last paragraph. We return every WR, RB and TE. Petras shouldn't be a downgrade from Stanley. Britt should be an upgrade over Paulsen. We only lose Ojemudia in the defensive backfield but will have Brents back. Our defensive line is almost always solid. I don't see 2020 as a rebuilding season.
The interior line was poor this year. Surely if they had someone that was an upgrade, they'd have plugged him in. They lose a starting tackle, and the QB is new and did not impress when he did get playing time.
If the QB has neither experience nor time, I don't see how the ball gets delivered to the WRs and the TEs that are coming back. If the interior line is bad, I don't see a back on Iowa's team that can consistently make his own holes for 4 ypc, 20+ times a game. I agree the defense will be fine. 7-5 is only two games different than this year, and with those handicaps I think it is OK to call it a rebuilding year.
Say what you want about Stanley, but I think we lose the Minnesota and ISU games with Petras at QB.