Honestly I think the reason has to do with run support .
The corners don't appear schemed to support the run D as much as safeties are.
Either Joyner or Johnson are set near line backer zones and have responsibility to watch run first.
The CBs are almost always singled up on at least one side .
All the opposing QB has to do is find out which side has single coverage and throw there.
In the case of one receiver eating up coverage all over field like Thomas did ...
Kinda insane .
They should have some kinda half man half zone and LB dropping in zone .to stop that.
Maybe that's where you get the Kamara effect.
Maybe they just don't have a way to stop him in backfield without commiting a safety and both inside LBs hard towards run.
So maybe it's a somewhat unique problem with elite RB talents that just busts this defence with size challenged guys like Barron and Joyner.
They have to commit bodies to stop run first but it often fails that way too .
