Simple: leadership ability which i firmly believe is a trait you are born with. Some people have it, others dont.
A leader can have subordinates do whatever they are told because they believe in what the leader says and sometimes they do it just to feel accepted by the leader. Think about it, why would a six foot two, 280 pound guy as tough as nails do everything carlo gambino or anthony casso told him to do???
Leaders carry themselves in a certain way. Some leaders are kind of introverted and keep to themselves but yet they can have 100 men do whatever they want.
I also think intelligence is a factor.