Aren't director boards majoritarian? Isn't the whole point that the board has the power? A coup or power grab would be if the CEO managed to convince a minority

Aren't director boards majoritarian? Isn't the whole point that the board has the power? A coup or power grab would be if the CEO managed to convince a minority of the board to work in the CEO's favor, to the detriment of the majority. I'm not even sure how that would work.