I would put it this way. Its hard to have the intimidating, killer mentality we had with the LOB when your D Line is getting beat at the LOS repeatedly. It begins to matter less whether you've got dogs at LB or DB if you lose the physical fight / battle of wills in the trenches.
With Murphy in, whether he shows up on the stat sheet or not, you can see and sense that more often than not we are engaged in a war at the LOS and more and quite often, winning the battles that happen there. Where for the last 8 or so years, you would slowly see us wearing down across the line, now, you are beginning again to see our guys getting movement into the backfield quite often and especially later in games.
He may not being popping off the stat sheet yet, but he is absolutely changing the tenor of the battle in the trenches and giving us an edge against opponents, even if ever so slight.