If Phelan and Martin were so good, then I am sure that the likes of Barcelona and Bayern will do anything in their power to sign them up, wouldnt they?
Its very common in football to have managers employing yes men. In fact nearly all managers come with their own repertoire of 'staff' which they insist to employ once they get the job.
Some are decent, others are just yes men who would fail miserably once they try to do something else. Do you remember how the great Choccy, Rene, Kidd and Queroz faired once they left OT? I guess to do. Others have more sense to retire once their protector had decided to call it a day.