SS uses more zone coverage. Zone coverage requires more communication between players when the opposing players pass from zone to zone. Players need to communicate the zone handoffs and the duties within a zone. (Man requires less communication, as you are only required to defend a man instead of a zone).
Zone defense not only affects the defensive backs but also the linemen who will drop back more into coverage. Now we can see why SS uses 4 linemen in a 4-3 scheme. This allows more versatility for the linemen. There is not one nose tackle playing the middle but a left and a right inside tackle. Defensive ends can also play inside on passing downs, adding even more versatility.
Zone coverage also allows defensive backs more opportunity to watch the QB instead of their man-to-man matchups and creating more opportunities to see potential turnovers. Playing the zone gives the safeties and corners better positions to make plays.
All of this is predicated upon whether the players understand and can communicate SS’s zone schemes. Understandably, the Saints embrace the opportunity to play five preseason games in order to install its new defense.