distance running is actually very complicated.
think of all of the workouts that sprinters do, they are much more frequent, and i'm sure you do a fine job thinking of and preparing those workouts.
distance runners on the other hand, especially if they run cross and the longer events in track deal with A LOT more volume of a different kind of training.
they get better not just from workouts but from running, running is what makes them better at running.
cross country/track runners deal with macrocycles in their training, it is thus the coaches job to deal with the beginning middle and end of each cycle. he wants his athletes to peak at the right time just as in sprinting and not burn out.
i may have a bias being a long distance guy, but i feel like since there is so much volume involved and by just the general nature of the sport, there are more pitfalls in the training and conditioning of a long distance athlete, injuries, peaking too early, knowing which workouts are best for the athlete to run well, and importantly AT WHAT TIME you do a workout in season.
sprinting focuses on form and muscle development, and in the long sprints tolerance to fatigue while distance running involves all those things on top of the main thing of training your body's energy systems, it's a huge physiological thing.
chances are, your head coach's office is filled with books on distance running and he has certifications by the USATF (1,2,3)