Dennis Stevenson
Twice in my career I've been a part of management or leadership teams that haven't really worked together as teams.

Don't get me wrong, both teams were loaded with talented and smart people. In both cases the team was committed to the success of the business. This wasn't a simple matter of "we just don't get along". Not at all.

My thought on this...

• Managers committed to the success of their individual teams are a hallmark of the management non-team. This is very easy to do. Going up the ranks, people are often rewarded for their ability to lead a team and get results. This is a normal function in most organizations. Being in middle management, the goal of a leader is to execute the instructions handed down to them from their leaders. The focus is downward and on getting the work done. When a person gets to the management team level, that changes, and downward focus becomes a liability.
• Managers who don't manage are a fatal flaw for any management team. Often a manager can survive the lower ranks by doing the work themselves. If the manager is the strongest performer in their organization, often they are focused on doing the work surrounded by the cast of their organization. To have a strong management team, this won't work. Managers have to manage their teams. No two ways about it.
• Managers who are overloaded with tasks don't have time to be team members. Being a team actually takes time. And managers who are loaded with time commitments don't have time to really be a part of a team. This is something that seemed to feature prominently in both teams that I've been with.