Well I think you are mistaken that he relies more on dropping into coverage and causing turnovers.
The problem is that we cannot be sure that if we rush 6 or 7.. we will hurry the QB.. our front 7 is not good enough or consistent enough to garuntee that. So, if we rush 6 or 7 and dont hurry the QB.. you end up getting burnt.
there WASNT enough talent.. our Dline is not doing what a 3-4 Dline needs to do.. they are not tieing up blockers and freeing up our OLBs. Dom's objective is to give pressure with a 4 man rush, and allow the rest of our defense to play coverage. That way, when we rush 7.. we can expect either a hurry, or a sack.
SO.. you cant really say that Dom's defense isnt working or that he runs it different.. when he doesnt have the personel that the steelers have.