The final 53 let's take a look

[Joelist]

They may be thinking to play 3 CB and 2 Safeties with 2 LB and 4 DL. The 49ers won Super Bowls with an alignment resembling that. Essentially CB #3 is a “safety” schematically and Safety #2 is a “Linebacker” schematically. If you happen to have a thumper type of safety (which we do) the defense can also deal with power running.