Why are your lower level managers in this department so hostile towards their subordinates? If you wonder why employees feel the way they do and perform on the level they do, you may want to have someone watch your managers closer. I think you holding leadership more accountable is an excellent idea as you have finally realized that the attitude, quantity, and quality of work by the subordinates reflects your lower level LEADERSHIP. Your employees are only as good as their immediate leaders. Think about it. So when your lower level leadership tells you that it is not them it is the employees you should investigate this.