When the Green Bay Packers announced that they’d be transitioning from a 3-4 defense to a 4-3 defense under new coordinator Jeff Hafley, the assumption was that the team would be getting smaller on the defensive interior. Because Hafley wants to play a safety in the box so frequently, the Packers will be down an extra player in deep coverage, which means that everyone on the line of scrimmage will be asked to rush the passer first, rather than the gap-eating buy-time-for-our-safeties-to-add-to-the-box mantra that Joe Barry deployed with the same unit.
You don’t have to look much further than the San Francisco 49ers and Houston Texans, two squads that the Packers have compared their defensive scheme to, for examples of teams going smaller on the line of scrimmage.