I remember when the story of the firings came out. There was reported to be some justification for Hoke, but I always felt like Imamura was a scapegoat for Richard Rodgers.
(seriously, who blames an assistant position coach for a unit performing badly?)
I'd say we've got better secondary coaching now with Perry Fewell (though I do wish he'd do something to improve the tackling in that unit) but worth remembering that Fewell didn't replace Imamura. He replaced Rodgers.