at this point of the season, you really can't make major changes in the schemes. you can tweak some things, but any changes are going to have to involve personnel and attitude.
maybe the change of DC will allow the players to catch their breath. the players aren't stupid - they know people are blaming them for the team's struggles. so, having a different DC, maybe with a different approach, could be the change of pace they need to regroup. You can't play scared - that just leads to playing tentative, and leads to more mistakes.
So, hopefully, guys can play a little looser, and the coaches can use the last three games to hold tryouts with the true FR and anyone who hasn't logged playing time yet. As for the "not ready to play" argument - the guys on the field don't look ready to play - how much worse can the guys on the bench be?
with the new red-shirt rule, there is no reason not to play every kid on the roster. can't get any worse.