There's nothing wrong with Hartis, so he probably stays, and McKenna is highly rated - but clearly lacks the experience to do the job at the top level. Give him a few years as a suplementary tactical coach under someone decent and he'll do fine. Carrick I have no idea about - but let's face it, the problem is that they are too inexperienced to be the leading coaches, not that they are really terrible coaches and can't function in a more professional environment. For all we know they could probably do a job as regular coaches working under more experienced head coaches.