While commanders do need to be confident, not every leadership style
fits every historic situation, or every type of unit commanded.

One classic on leadership is John Keegan's _The Mask of Command_.
Alexander the Great and Ulysses S. Grant were superb commanders for
their responsibilities, but it would have been disastrous if they were
switched. Alexander's armies needed a visible heroic warrior literally
leading them, while the grand strategy Grant executed required what
Keegan calls "unheroic" leadership in attrition warfare.

The commander of a combat wing has to give the impression that he won't
issue an order he wouldn't try to carry out himself -- and will also
know what specific things where a subordinate knows the techniques
better than the Head Honcho in Charge. A field hospital commander has
to have a different personality, especially when making triage or other
resource decisions to let a wounded man die. A very different kind of
leadership is going to be needed in a highly technical combat support or
combat service support unit, be it tactical transport or electronic
warfare.