Some people have a hard time working with others when they are put in positions of authority. This whole situation reminds of a lady we made our office manager and later had to fire. She was a competent paralegal and had seniority, so we believed that the logical progression was to make her office manager because the firm had gotten larger and we needed one at the time.
Once given some authority over the other ladies in the office, she developed what I would call a serious "Mother Hen Complex." She micromanaged and didn't do it nicely. She let the other ladies know who was boss rather than treat them as equals which she basically was except for her title. She developed into a divisive cancer. Sadly, she was a completely different person out of the office. It was a personality issue in the office. Her successor was another paralegal who did a better job and actually became something of an advocate for the other paralegals to the point where I felt she was their de facto union leader as she would complain about me giving them too much work. I told her I am a machine and they gotta keep up with the machine, LOL, tongue in cheek of course. Now we have another office manager who is a bit more educated than her predecessors (has a masters degree from Fairfield U., which commands some respect) but she doesn't politic and is very diplomatic both with the paralegals and the attorneys. She tries to stick to her job of overseeing the office's finances and administration, and doesn't exercise her authority either to micromanage others or advocate on their behalf, sort of allowing them to behave and do their jobs. So their are different approaches to handling these authority positions and basically I think it's all personality and style. Your directrix who was fired sounded like a micromanager and they eventually cause irritation with too many people and either have to dial it back or get fired. Hopefully she learned something.