Leadership Styles are Labels
I think most of the leadership styles we heard and read about are simply labels made by people, in particular social scientists, to interpret those demonstrable behaviors. They are after-thoughts
The very basic definition of "effective leadership" is to drive the best result/behavior that you desire from someone. It is therefore hinged on one's ability to influence others regardless of style. Effective leadership though is different from the end result of the leadership.
Hitler, Napoleon Bonaparte, Jesus Christ, Genghis Khan, Abraham Lincoln, Saddam Hussein, Mother Teresa have different ends in mind but they surely are strong leaders.
While leaders may use different styles depending on what they are strong at, it is important that they are consistent, authentic
, and most importantly, they believe in what they're saying... It's called passion and commitment.