The same circumstances could apply to fantasy campaigns. Even idiots with bad personalities can rule the land, provided even bigger idiots allow such an atrocity. High charisma scores and leadership skill dont truly help much when your using fear to rule the land. High charisma and leadership can help...but they are quite optional from any realistic standpoint. Only in an idealized society will such things truly function as they should. The world isnt fair....jerks rule the world, money rules the world, fear rules the world. But the world is seldom ruled by charisma and leadership. Jerks are only charismatic to the dimwitted masses. All you really need to rule is a tactic that works.
So...in conclusion...I wouldnt worry too much about the mechanics of charisma or leadership. It's a novelty to be charismatic or a leader, but not all leaders are either charismatic, nor are they particularly good at leading. Many leaders who have millions of followers are just good at letting the people around them do their jobs for them and fooling others into believing they are doing all the work.
He He He !!! You guys think too much!!!