In my mind we need fresh ideas, I am not a great believer of players moving to management/coaching roles within the same club. I have no objections for him to move away and come back a few years down the line though.
Not only is it for fresh ideas to be bring someone in but players moving to management/coaching can sometimes be difficult for them to adjust from a professionalism point of view from being one of the boys to being senior (it is the same in any walk of life). It can also be difficult for the existing players to adjust as well.
However it may be that Col already does some coaching at Alty and so the transition may not be as great. However for me I think we need someone fresh like GB was when he came in and lets face it, changed alot for the better (which is his job to do and why managers have assistants and coaches, so not a slure on GH)