I think the transfer portal crap makes it hard for most teams to have depth. 2nd string guys don't stick around to develop, they transfer to a new school. That means you have either inexperienced or under-talented guys in your backup roles, and if you get to 3rd string, woof. We have been to 3rd string in our secondary.
I also think Henry has done a poor job. If you know your secondary is a liability, you've got to get some pressure on the QB, and we don't do that either. I don't think we have the horses this year, which greatly adds to the struggles, but getting players is part of the job in college.