There are some good coordinators who are just not good head coaches. There are some position coaches who never develop the global skills to excel as coordinators. And yet still, there are even head coaches who are better at that task than they are at more the specific responsibilities of a coordinator or position coach.
I say this as a preface to a brief discussion about Pittsburgh Steelers defensive coordinator Keith Butler, who has been in that post for the past four seasons, but spent over a decade on the coaching staff working with the linebackers prior to that, from 2003 to 2014.