[mirko22]

When you start talking about introverts and extroverts you would first have to state to which ideas behind those concepts you subscribe to. If Jungian then you can be both introvert and extrovert in the same time.

If by wikipedia then you think they are exclusive and might even think that introverts are people who just want to sit at home.

Not wanting too much company can also be associated with highly sensitive people and not necessarily introverts. About 30% of highly sensitive people are in fact extroverted.

And there is no single trait or concept that makes someone a good leader but rather a mix of lot different psychological and biological setups.