Campbell isn't the problem. He does have ball security issues, but it's not like this is a big surprise.
The problem in the run game is the overall scheme. We continue to try to fit a square peg into the round hole. The Zone blocking isn't working. If you look at the successful runs we've had they have mostly come on Sellers leads / ISOs or on what appear to be designed cutbacks off the Zone blocking. Our OL isn't a finese OL, they aren't particularly fast, don't cut, and aren't great technicians. A more basic straight ahead scheme suits them better. A trap or counter never hurt anyone and I've seen very little of those (less than 5%). Portis is not the back he was in Denver either, he's more suited to a "between the tackles" style.
When
you circle the wagons and go back to basics.
Quick story, it's certainly not the NFL, but the philosphy applies. Our HS JV team was undefeated for 5+ years. JV scrimmage, we're blown-out 40-0. Completely embarrased. Coming off the field a parent says to the JV HC, "You and your coaches should go hide". We looked at film, identified basic fundamental problems, lectured the kids about effort and what we expect going forward. Told anyone who didn't want to be there, they were free to turn in their stuff in private after the film session.
No one turned in their stuff, we had a great week of practice and went on to go undefeated.
Circle the wagons, simplify the run game, become aggressive on D. We'll find out a lot about everyone in this organization over the next 2-3 weeks, including the FO.