Ruben Amorim's dogged insistence that his style is not for changing only serves as an enormous gift to the weaker-minded of his Manchester United players.
It's an excuse and weak-minded players always love an excuse: it's the system, not them.
Amorim is not the first manager in recent United history to try changing to three at the back. Louis van Gaal did the same when he took over and look how that played out. He changed after being confronted by Wayne Rooney and Michael Carrick who told him the dressing room was unhappy.