The 5th man on a HS cross country team? He probably doesn't need to worry so much about weights, sprints or plyos...he just needs to run.
A college guy trying to break 15:00 and is already doing 'complete' training (getting in the long miles during the off-season, quality workouts, etc) he probably needs weights and plyos. Most college programs are good about doing "strides" post-easy run. So that's one good thing. Most programs are horrible about weights and plyos.
Alan