I think a lot of students and teachers place too much blind faith in martial art instructor credentials.
John is a cop, therefore he is a qualified shooting instructor. Jake was in the military so he knows everything about combat. Jack lives in Japan and is a Shihan with 25 years of training so he knows the true secrets of taijutsu.
To me, credentials are simply a starting point to take a moment to listen. It’s just a little bit of credibility. It doesn’t necessarily mean what that person says is the best. As students, we have to keep our critical thinking cap on. It’s okay to be skeptical.