If you are training to run, the best thing to do to improve your running ability is to run.
If you want to be a good coach, the best thing to do to improve your coaching ability is to coach.
Ill take the guy who has spent 20 years coaching vs 20 years running
Here's a thought, the best coach might not make you the best runner you can be. We can subjectively say one is a better coach based on his or her athlete's results, but if your training style fit in better with another coach, wouldn't you be better off with that one. Too many variables to really know. A good coach is in tune with his or her athletes' needs and goals.
The one with the better runners
False dichotomy.
In any case, I'd rather go with the better *coach*: the person who better understands people and their motivations. I've worked for a guy whose team won the NCAA cross-country meet, and he was no distance runner (to put it mildly). Frank Gagliano and the late Norm Levine (another NCAA winner) have also had a fair amount of success in coaching distance runners, and nobody would guess they had a personal background in the sport.
By the same token, I've known former runners who were great coaches, and others who really sucked. It's much more a question of what kind of *people* they are, rather than what kind of athlete (if any).
I think its interesting people rank old school DI coaches as greats. No these non-runner coaches just had all the recruiting advantages and got very good athletes.
Even Vigil had an advantage being at altitude and he became an expert at it, before anyone really know about it.
I think really good coaches are former runners who didn't run competitively much after college. Competitive runners tend to be selfish and think everyone should train like they did. While those that give up competitive running and focuses on the individual, is focused on coaching rather than what is advantageous for themselves.
There's a high school coach in my state that by the looks of him (very overweight for as long as I can remember) either has never been a runner or hasn't run in very long time. Yet he consistently produces top 5 xc teams in the state year after year, especially the girls team. Not sure what his approach is but it is certainly successful.
Coach who has observed runners FOR SURE.
Running your whole life only teaches you how to coach yourself. Coaching runners is an interpersonal skill, you could be good at it even if you didn't run at all.