When a subordinate distracts you with some small matter unrelated and unimportant to your present chain of thought, what facial expression do you have? Little things like facial expressions and your reactions to trivial incidents are extremely important to the relationship you have to subordinates, especially when you have many subordinates and you cannot form a deep relationship with all of them.

I think this is one of the reasons why so many generals are incompetent tacticians, and many of the greatest tacticians are not generals. There are certain personality traits you have to be born with, they are outside of your conscious control.

The admirals role, I think, is more under his conscious control.