It is important that McCarthy surround himself with a staff he knows and trust. All coaches know when a new HC is hired there is a good possibility they will be fired. These are not newbees to the coaching profession.
that basically is what it's coming down to. Familiarity and cutting away the coaches learning curve, and wanting to hit the ground running.
He'll know what to expect from a coach he knows.
He won't have to come over in games to find out what went wrong and what is transpiring between his asst. coaches and WR personnel.
if something is going on with WRs, and his very well knows his own WR coach and agree with the way he works, he'll already have a lead for what's going on and
addressing it.
Because of this, I am actually surprised that he is still keeping Kellen Moore on board, instead of trying to bring in his own familiar OC.
So what elements has impressed MM about Moore such to consider retaining Moore ?