In every field you go into, there will be people who have big egos. If you go to a university, you'll find professors who have big egos. If you go to a rec center, you'll find sports coaches who have big egos. If you go to a dance academy, you'll find dance instructors with big egos. And yes, if you go to a martial arts school, you might find martial arts instructors with big egos.
But guess what you'll also find in all of those places; people who don't have big egos. In life, some people have big egos, some people do not.