Aristotle thought the best ruler would be a philosopher-king. It's true they're hard to find. But common sense is not very common and a good heart is too often a class issue.
A leader's qualities should be suited to the times - what works in war doesn't necessarily work in peace and vice-versa.
When all is said, leadership is still a somewhat mysterious quality - but I'll always prefer intelligence to stupidity.
Just as a personal note, my son is an architect with aspirations to become a teacher. My daughter just graduated in building construction. Guess which one is the leader?