We are so mentally wedded to the idea of the base 3-4 defense that we just aren't seeing reality - which is that the primary purpose of the third ILB (2nd?) is to play special teams and maybe serve as an intermittent replacement due to injury. Are not most special teamers even more fungible than long snappers? Aren't these the guys that last roughly 1.5 seasons?
And given the increasingly dwindling role of ILBs in the NFL? Aren't they becoming the defensive version of a fullback? How often do teams draft fullbacks anymore? Much less their third fullback?
If you're cool relying on Shazier to stay healthy more power to you and Williams is an unknown how he'll perform over a full season. Let's not forget that Shazier was most effective when Timmons was performing well last year.