I've seen QBs and other players on the sideline who exhibit traits I see as consistent with future head coaches. Being a vocal and motivational leader is a much better indicator in my book than whether you can read a defense or learn a playbook. Tommy simply doesn't carry himself in a way I could ever see boys above the age of about 14 looking up to and taking direction from.
I have all the same questions Kane had, plus I don't get why we are now talking about whether Rees can be a future
head coach. The original question was whether he had a future in coaching, not whether he could be a head coach.
Even if we assume that you are right and Rees doesn't have the attributes a successful head coach must have as you've described them,
(but let me be clear ... I do not actually agree with that conclusion because (a) I put more stock in what Kelly and Rees's teammates have said about him than in your belief that Rees doesn't carry himself like a leader so he must not be one, and (b) I also do not accept the premise that a player who does not have a certain bearing as a fiery, vocal motivator is not a good head coaching prospect),
a coaching staff surely needs someone who can do the things we know for sure Rees can do ... break down game film and teach players how to execute a particular system, in addition to vocal leaders/motivators. Why would the fact that Rees isn't a vocal leader/motivator (again, assuming it's true that he isn't, contrary to what we have all heard he is, based only on your assessment of his bearing) preclude him from joining a coaching staff in any capacity?