I'm going to be radical here and say that if the flavor of your Dharma centers are really as folks are describing above, and its been around more than 10 years, it is a failure of the teacher in charge. He or she should put an end to this kind of behavior. If people are becoming more arrogant, jealous and competitive, their practice is going in the wrong direction, and they need to be firmly redirected.
That being said, when a new powerful teacher comes to an area he or she will attract a wide variety of people, some are going to stay and practice diligently, and some won't. Actually, where there are already existing centers, the new center or group will attract the people who could not get a long with the others at the old centers, so there is often an influx of difficult people at the onset.
From the managerial point of view, it takes a long time to learn to work with people and their various expectations within Dharma groups. The leaders will inevitably make mistakes. So, if the center is relatively new, there is something said for being kind and patient with the people who have been put in charge. It may or may not have been their preference to be put in this role.