Yeah, that's all well and good, but it doesn't give me any clear indication that the defense, as a whole, didn't work last year. The scheming in games was put in place by Fisher/Williams with Williams making the calls while Fisher had a veto option. So Fisher signed off on most of that defense last year.
Playing off coverage was addressed by Fisher during the year. When you have two rookie corners who don't have a single memory of any receiver in the league, or any idea what their tendencies are, you want to keep the plays in front. Particularly if you have safeties who are basically a liability in coverage. Fisher's whole MO is to make opposing offenses be methodical in their drives and stall them on third downs. That's what they did with the exception of one game (NE).
To be clear, I'm not arguing against you here. It frustrated me as well to see those huge cushions being given up - even on third downs. But do either of us have the experience to say that what Fisher and his defense was doing ... was dumb? Do we really know what their limitations were with two rookie corners, a rookie DT, a new DT switching from 3-4 DE to 4-3 DT, and two new OLB's? I certainly wouldn't be that presumptuous. All things considered, I think they did a fine job against some pretty decent teams. It can get better, and will, but I wasn't expecting the world with all that new personnel in a new system. They actually (by far) exceeded my expectations.