Just my observations.
Metrics - however Cavanaugh is choosing his fab five, something's wrong. In both year 1 and 2, players came off the bench and played better than their fab five counterpart. It makes me wonder if other players on the bench are more worthy of playing time than we are led to believe.
Fab five and the rest "can get better on the scout team" - the expectation level and commitment to being better can be different when comparing preparing for the next game versus just going to practice. It makes me wonder how much time & energy does Cavanaugh actually give to the non fab five. And please before someone feels compelled to argue, if you've been involved in athletics and you weren't one of the superstars, you'll know what I mean. It also makes me wonder how much 1st team practice the non fab five get.
The hardline approach - It's his way or the highway, rigid thinking. If he were the most celebrated and successful OL coach, it would be foolish to question changing what you're doing. But he's not, so it just looks like doing the same unsuccessful stuff over again and expecting something different.
The pipeline - we substituted players in order to make the whole better. And someone on this board actually went and watched old games, iirc it was 3rd series substitutions not just mop up duty in blowouts. If quality reps are only coming after an injury, there's no reason for me to expect a pipeline. But we don't have the depth? Refer back to players coming off the bench and outperforming the fab five.
Retaining Cav - I really don't care whether he's coaching the OLine or someone else is.