I think the more interesting question would be on Myers-Briggs typing. Intraversion/Extraversion doesn't really matter all that much in Pokemon. It would be interesting to see MBTIs of top players and look for a pattern.
ESTJs thrive on order and continuity. Being extraverted, their focus involves organization of people, which translates into supervision. While ENTJs enjoy organizing and mobilizing people according to their own theories and tactically based agendas, ESTJs are content to enforce "the rules," often dictated by tradition or handed down from a higher authority.
ESTJs are joiners. They seek out like-minded companions in clubs, civic groups, churches and other service organizations. The need for belonging is woven into the fiber of SJs. The family likewise is a central focus for ESTJs, and attendance at such events as weddings, funerals and family reunions is obligatory.... etc