they have both had 2 years as coordinators. Howell's first year was actually pretty good. Last year was dismal. Doman had two terrible years.
Howell did luck out by having Bronco able to come back and work with the D.
Because Bronco is a Defensive specialist, he needs someone who he can just hand the offense over to and not think about it.
In both cases, I think Howell and Doman were respectable position coaches. They just don't seem cut out for coordinator spots.