Define good coach.
If you mean winning coach, at the college level you almost certainly must have been a good athlete to get any job.
Often we see coaches of other events coach cross country (as it is regarded as not important by most A.D.s).
But runners will go to places that have winning traditions regardless of how successful the coach was as an athlete.
The best combination is often an average level athlete who gets a few years of experience coaching. But there are very
few examples of this at the college level.
At the high school level sometimes you will see a football/basketball/baseball coach do well as a cc coach. All you have to do is read a book and watch videos now. That does not mean they are "good," coaches by my definition though.
A good coach teaches athletes about life and encourages them to run after high school.
The best thing to do is put circumstances out of your mind if you are a coach as anyone can win with any kind of background.
Anything is possible. But winning should come second to caring about people.