I think there is also GREAT value in a man being certified, tested, authorized - and in constant accountability. Not SELF approved, SELF certified, SELF evaluated, SELF authorized - or maybe by ONE person (whose own credentials aren't so good). For at least 1600 years, pastor had be schooled (extensively), their profs examined them (and not just academically!), when they had completed all their classes, boards questioned them, examined them, evaluated them - and possibly approved. Then a bishop went through the same process - and possibly approved. A bishop had to be involved in their placement. And all the while they teach and preach, several likely with MORE education, MORE experience held him accountable, examining his preaching, his teaching. I think there is value in that. All that was largely abandoned by the mega Evangelical church I was aware of in my teen years.
Again, I'm NOT saying all that INSURES anything..... but I think it has very great value. And since truth matters in Christianity, it should be a concern to all about "the blind leading the blind," the ignorant teaching the ignorant, the unaccountable teacher (lightly subject only to those who know even LESS than he does).