I know this is hard to believe but sometimes guys and their systems just get stale. It's quite possible that Marinelli's scheme just doesn't work well in today's NFL.
It's entirely possible and I don't discount it. My opinion is just that he hasn't had very much talent, and the one time he got it, those impact players were marginalized by injury, other factors, and a season that was lost three games in. I really have a hard time shaking that.
The first two and a half games of the season (cherry picking I admit) I was very impressed. Shut OBJ down, destroyed Demarco, stifled Julio, held in the redzone and looked to be a very competent unit. That disintegrated very quickly (after weedens INT on our side and some creative usage and movement of Julio ) but it impressed me.
Hell they were beating the patriots up until they started setting picks, and by that point the wheels were falling off the season as a whole.
As far as other teams being able to overcome injury, the vast majority of them have had more talented units to begin with. Next man up is a difficult prospect when the first man up was already the next man or the one after him lol.
Worst part is that the odds of him redeeming himself this season are already slim with the release of Hardy, selections of zeke and Jaylon, suspensions etc. Was already behind the 8 ball.
The offense has had the luxury of having an elite qb under center for the past ten years and either a top five receiver, rb, te, o line or combination of all of the above. The defense has damn near been the complete opposite. The two times in the past 6-7 years that they've made an attempt to upgrade its backfired in Claiborne and Carr, and Hardy and Gregory. What do you expect him to do?