I've never been a highly recruited athlete, but an analogous concern exists in med school. Kids who have had enormous academic success since elementary school suddenly find themselves on the left side of the bell curve in med school. It's a struggle for a lot of students, and plenty of people have to adjust expectations in terms of specialties, BUT almost everyone figures things out and makes it through ok.
You'll never hear of an adcom with a policy of rejecting all 4.0 students simply because those students might not take failure well. You do your best to accept people who a) have the intellectual capacity to succeed, and b) really want to become physicians, and you hope that A and B together will allow the student to push through the tough times.
I think the same should apply to running. Look for talented runners. Use your face-to-face time with the athlete to gauge their passion for the sport. An athlete who is talented and passionate will figure out how to navigate any early disappointments.