no offense to MR and EP, but I would much prefer a veteran ex-head coach sitting beside Chris while he learns the nuances of being a head coach
Oft repeated but Frank McGuire once said something along the lines of, "You coach and I'll get the players, and I'll beat you every time." Jimmies and Joes before X's and O's.
On the topic of game experience, John Wooden often said that most of coaching occurs in practice. He maintained that timeouts "are a sign of weakness".
If you follow the Wooden theorem, there may be no one better suited to run a practice than Mullin.
Having an experienced coach next to him on the bench may be more for our comfort than his.