https://www.pro-football-reference.c...g_advanced.htm
PFR doesn't explain their definition, so I'm not sure where to find blitz numbers by number of rushers, but according to this Cam was blitzed an absurd 48% of his snaps (#1 by far, from what I can tell). Despite being dead last in attempts by starters he was: 12th in sacks, 17th in pressures, 10th in pressure%, 9th in total blitzes, and 1st in blitz%.
This is why I'm saying the top 5 OL comments aren't really accurate without context. It must be strong individual performers carrying the weak performers who are causing issues or something. There were games in the back half where Cam was being hit before completing his drop back because the replacement LTs were awful; so maybe the OL was grading stellar from LG to RT, but if the LT is killing the play play before it even begins it doesn't really matter.
Based on the advanced pressure stats, I have to imagine the run blocking is why they're so highly rated. Their run blocking was stellar even when they had injuries.