One of the most famous quotes attributed to Alexander the Great is when he insinuated that he was more afraid of an army of sheep led by a lion rather than an army of lions led by a sheep. The reason being that battleground calls for exceptional leadership, command, organizational capabilities and inspiration from a central figure.
A leader is a person who is able to bring out the best from his men no matter the circumstances. He is supposed to be visionary and capable of thinking on his feet.