Actually...no it's not. Nolan isn't going to change his scheme....Did you see some of the crap he was trying today? He had Aldon Smith playing OLB in a traditional 4-3 in space....WTH? the guy is a defensive end...Think your gonna see some really absurd lineups in desperation in the coming weeks.
Nolan has installed a complicated scheme, far different than what Marinelli did. That requires time, remember there were no OTAs, mini-camp or preseason games, so the team is "learning on the fly", and that's difficult to do. If nothing else, the players have to be evaluated as to whether or not they can handle the assignments. And playing Smith in a different spot was probably an experiment, if it didn't work, probably won't see it again much, if any. Didn't we all gripe about how we had a "vanilla" defense, teams knew what plays the Cowboys ran before they ran it? And Marinelli's scheme not working, being outdated and not having the players needed to run it?
So now we have a different scheme and coordinator, and after 4 games the sky is falling.
Well those of us who've been fans for decades have seen changes that didn't work for a while before, some were calling for Jimmy's head after 1989, the "he's a college coach, we need a real NFL veteran coach". But eventually he molded the team into what he wanted and it won 3 Super Bowls.
Now don't think I'm saying it's all good, the defense will turn it around in a few weeks and be top 10, that's unlikely to occur. But it was unrealistic to expect Nolan's defense to be an immediate success, and losing McCoy right away, and now LVE, Awuzie, Brown and Lee (who's not what he once was, physically, but he does know how to read offenses better than Smith, et al.), players that do have experience and at least camp in the new scheme but aren't on the field.
And don't discount the effect that the turnovers by the offense has had. In this last game, why did the Browns have so much rushing yardage? Gee, think having a 31-14 halftime lead might have something to do with that? And running is their strength, did anybody expect we'd shut down their running game?
Fix the offensive gifts to the opponents, if they can, and this defense by that reason alone will be better, at least score-wise...