some of this is forced because of missing guys and poor LB play.
Part of it seems to have been planned from the beginning. We brought in both Neal and Kearse apparently with the idea of playing them as pseudo-linebackers, so we're in nickel and dime looks a majority of the time, but we're actually playing three LBs (Parsons, Neal and Kearse) with Kazee, Hooker and now Wilson rotating as the two safeties. The decision to play bigger safeties as linebacker/safeties is throwing teams off because you don't want to run against a stacked box, but we're stacking it with hybrid safeties who can more easily drop into pass coverage.
I think Quinn may be ahead of the curve on this. With teams passing more, it makes more sense to use safeties who can play the run but also cover some over traditional linebackers who are bigger liabilities in coverage. Even Cox fits that mold although he's a traditional linebacker.