Philly doesn't use a traditional front 4, they switch up alot and go hybrid with 3 up front and bring in safeties and corners on snake blitzes
They've also got depth on the front line bringing in excellent pass rushers
It all starts with cox as the best and most impacful pkayer on the line. Everyone else ranges from solid to bordering on great. That Barnett rookie is going to be a stud. Brandon graham is an edge rushing specialist