What I am suggesting is it is a team, and it is the head coaches job to go to the GM and say, I need a better LT, LG, and DT.
GM says, it will cost this much and you will need to cut someone, your choices are we can sign Corey Simon, but need to cut Eric Moulds. Are you willing to do that?
I can trade our 1st pick for Ogden, but you also lose Nate next year, are you willing to do that.
The coach then has to decide his priorities and tell the GM whether he is willing to sacrific one for the "benefit" of the team as a whole. Either MM is not doing that, is letting the GM push him around too much, or he is unable to coach to the decisions made. Either way, MM is just as culpable or more so than the GM, since it is the coaches job to design schemes to win.