Physical courage is performing an action despite the fear of physical pain or death. Intellectual courage is overcoming the fear of complication and the natural aversion to feeling confused. Moral courage is doing what you know to be right regardless of the potential negative personal consequences.
It’s possible to have physical courage and be neither intellectually of morally brave. It’s possible to be intellectually courageous and have no physical or moral courage. However, it’s impossible to be morally courageous and not possess the other two. If you are morally courageous, then you will also be, by definition, physically brave and intellectually brave. Therefore, it is moral courage that is the rarest and most potent of the three.