Yes, three different DC's and when you look at them one was moderately successful, one was very successful and one failed.
All 3 had essentially the same personnel. One joined the team when the defense was downtrodden. He made it fun for the players and the fans. Couldn't stop the run, but, he was successful enough in his one year stint to land a HC gig. One joined when the defense was on the upswing. He made it fun for the players and the fans. He stopped the run and defended the pass. We was successful in his one year stint but he was fired by the incoming HC. The incoming HC took basically the same personnel grouping and turned it into a hot mess.
1 one year stints.
One turned things around to the good.
One built off of that turnaround and made things better.
One couldn't get plays or personnel groupings into the game on time.