The coaches only follow the managers lead, so anything wrong with the coaching set up, is down to the managers training tactics, (or lack of).
From what I've seen since Mr. Bruce took over, the problems are, that instead of having a way of playing and getting in players to play that system, we continually buy players who have been their previous clubs top player, ending up with 11 players used to 11 slightly different systems and expect them to gel into no system at all.
While on paper we end up with a theoretically strong squad, in reality we end up with 11 strangers with no leadership, wondering what they are supposed to be doing.
At the rate we are going, we'll be lucky to get promoted this side of 2030.