Kelly's doing the best he can here and it's plenty good. No one REALLY figured on the sudden departure of Lynch, so you'd have three near-All American quality true D-Linemen in Terry's first list. Day and Jones were rated very high coming in behind, and we had the inside information that Okwara was a preternatural Earth-mover. That's three more.
Our D-Line is evolving into a shared 3-4 and 4-3 as a regular substitution pattern. The thing that actually EASES pressure on getting D-Tackles is that Diaco is going to slide the Earth-mover DEs inside [a la the NYGs] and get TWO CAT/Crash linebackers to be rush DEs. Suddenly someone like Shembo becomes a dangerous DE instead of an OLB. If necessary, Rabasa can do this too, but he seems growing as an ILB to me.
We are fine this season and probably next with this pattern [three deep at almost every variety]. The only thing that we lack, is another true NT like Big Lou, and they are rare birds.