Still don't think that is a success as he was making us perform which is what we should be doing. I guess you could argue our least real success was Micky Adams who "succeeded" in helping us finish 8th in the Championship.
I can think of two who "succeeded" in over 50 years; Hill and Sillett. THe others either kept our heads above water, had patches of good form or, in Strachan's case "succeeded" in relegating us.