Going to a more zone-based scheme may work, IF they can get to the quarterback more consistently. The new guy they signed from the Browns, hopefully a healthy season from Chandler Jones, some blitzing from Jamie Collies... maybe Easley can take a step forward in his second season. But they've got to get that figured out - the pass rush has been so inconsistent.
Maybe they figure it's more cost effective to build the defense that way, given the cost of acquiring elite cornerbacks.