Murphy is a total liability against the run because he is undisciplined, he overcommits and does not maintain his gap. I doubt anyone can coach discipline into him which is why he should be a healthy scratch. I agree that Murphy will not be able to sack Lamar, though for multiple reasons. That is why I think Lorax might be a better option at edge.
Jackson does a good job of seeing and picking his holes, both inside and outside. This is why I think there should be two spies on Lamar, one for each side.