Joe is really a jack of all trades I would say. This is why people outside of this type of community do not tend to like him much. He seems very outspoken and likes to talk and act as if he is the leading mind in all subjects, will frequently interrupt his guests and interject with facts just trying to sound smart/smarter than his guest and sometimes you will even have the guest correcting him since he is not actually an expert on anything while they usually are.
If Joe Rogan is anything he is certainly charismatic. He is also intelligent but I would say that his charisma outweighs his intelligence. When this happens you get an outspoken person, someone who talks more than they know. I am very much the same way and often talk a bit more than I know about a subject and people tend to believe me when I am not 100% on the information or did any research.
Joe does a lot of research though and is very on top of his information most of the time. I love him. Don't always listen to his podcast but I love the guy. He's funny, intelligent, charismatic and the best damn fight announcer/analyst in the business of fighting the world over.