The idea that certain kinds of people gravitate toward certain kinds of leaders has been around for a long time. There are exceptions and degrees of commitment, of course. People (as individuals) are complicated and changeable. On the other hand, people (as groups) are remarkably consistent and predictable.
There are patterns. The typical follower of this leader has these characteristics. The typical follower of that leader has those characteristics. Conversely, this group of people tends to look for, believe in, and listen to this kind of leader; and that group of people tends to look for, believe in, and listen to that kind of leader.
There are trends. Certain kinds of people are more responsive to certain kinds of leaders. Certain kinds of leaders seem to be more empathic toward, and understanding of, certain kinds of people. They seem to know some contexts, certain needs, and distinct attitudes better than others. If you follow the career of a leader, you can anticipate who they will gather around them and where they will be most effective.
Bandy shows how this is true for church leaders too and introduces ideas of different types of leaders attracting different groups of followers. Knowing your "type" will help you know who will be attracted to your leadership style.