Too many generals in the kitchen is not good.
More to the point, the number of flag billets at the pentagon has become a de facto “ticket punch” for advancement to more stars. That is not what is supposed to be - the general officers are supposed to be at the pentagon to lead and plan, not get their hand stamped for advancement. Those who do well (and focus on the mission and the troops) should advance. Those who are climbing the ladder systematically should retire.
As a former Army O-3, that is my strongly held opinion.