They confine themselves to policy-setting and oversight. They meet in private, then communicate their policy decisions to CEO David McCoy with one voice. McCoy, in turn, is the only official conduit for operating staff communication with the board. There is plenty of intermingling but no muddying of the lines of authority and responsibility. There trustees try to be both policy- setters and managers.
Campbell operations are private and taxable.
They pay the taxes. They also nominate their trustees. When there is a trustee opening they meet to establish criteria for a replacement, seek suggestions on candidates, then winnow their list down to finalists to interview. They recommend their final choice to the probate court. It could reject a nomination but never has.