Miandad is a cricketer whose contributions to the game are immense. No doubt about it.
However, in his playing days he was an abrasive personality and I would not be surprised that as a person he is the same. This may be a vital reason why his three coaching stints have been unsuccessful.
Bob Woolmer should coach the team himself without seeking Miandad's advice. At best, he could seek some other ex-coach's advice.