I think once DLaw returned from his injury the DL payed really well. However, there are some concerns I have. Gregory is one of the most undisciplined DEs in the league. In fact, the entire Cowboys DL struggles with discipline. They are talented and will get better when the young guys in the middle get some experience. But I see them out of position way too often. Gregory in particular takes himself out of a lot of plays by over-pursuing. Lawrence will do the same thing sometimes. Most of the time they can get away with it. But against mobile QBs it hurts the defense.
The difference between the Cowboys and 49ers defenses is the way the 49ers secondary tackles. Their DBs will come up and support the run defense and make tackles on the outside. The Cowboys secondary gets blocked out of the play or they just miss tackles. I think if you draft DBs who don't like to tackle eventually it costs the team.