Managers generally overrule other's opinions by giving promise of personally "coaching" the new hire to make them meet the bar. In most cases such people are put on a plan, ironically called "Coaching Plan" itself, and thereafter fired. URA quota is an open secret at Amazon, and some employee appreciate the practice of hire to fire, as it saves their own employment. That in turn ensures that objection to bad hire, who is going to be "coached" is non existent.