Compared to D-line and D-backs, this is definitely the area of most concern for the defense. I think Davis is very good. I really like Marcordes and believe he can be a good player. I think Hankins defends the run capably - not as sure about his value in coverage or blitzing. Depth is not impressive, but hopefully these players are developing in the program and are ready to contribute.
I do believe that the defensive line can't simply try to take on a blockers for linebackers to make plays. We will need the front four to make tackles against the run and get a pass rush to be better on defense.