I think anyone who has accomplished much in his chosen field deserves to be heard. I think you would enjoy reading "Become the Arrow."
OTOH, I do think there is a difference between great teachers and great doers. Einstein was a remarkable physicist, but I don't think he would have been very good at teaching a 10th grade high school physics class, other than the fact that the students might have enjoyed meeting the greatest physicist who ever lived.
Which goes back to Moebow's comment above: "As to finding "some 'coach' who may or may not know a whole lot about archery," if they are certified by NADA as a level 2 - intermediate instructor, level 3 - community coach, level 4 - regional coach, or higher; I respectfully submit that they MOST likely know something about archery."
I would rather have a coach who is not a champion archer, but who understands how difficult it is for the average person to master a skill, and who has the ability to teach the average person how to get to the next level. The problem with a champion archer is that they have a natural ability that most of us don't have and won't ever get. They don't make the mistakes we make on a regular basis, and never have. So it is difficult for them to teach us how to avoid them. Whereas a person who has had to struggle to attain a proficiency level that is higher than the students they are teaching, but lower than the champions, is better able to understand the difficulties the students are facing and help them to overcome them.