Why the focus on where he worked in high school? Most people, at least in my day, worked in high school.
German Fernandez already had injury problems in high school, which is why he didn't win the xc title after running a record 14:24, I think, at Mt. Sac. His coach really had to hold him back and limit his speedwork to keep him healthy in high school. He said that prior to the 4 flat 1600/8:34(?) 3200m double, the fastest work he was doing was at 60s pace, 200s or 400s. He was just 17 when he graduated.
Then when he went to Ok St, he was having a great xc season as a freshman, eventually running in 8th place at NCAA champs around 8k until he had an achilles issue and dropped out. Later that winter, to show how much he developed with the better team competition and higher mileage (and presumably much harder workouts), he ran 3:56 solo, then 3:55 for the mile and 7:47 junior 3k record while quite sick. At this point, he was just 18 years old. He went on to go wire to wire in the NCAA 1500m final for the title, again as a freshman, and run 13:25 for the 3k junior record.
Over the summer, he became a vegetarian or a vegan without understanding how to handle the nutrition and without telling Coach Smith, which led to him developing anemia and that also led to injury problems, which continued almost until the end of his senior year. Arguably, Coach Smith should have put him on a very slow progression in mileage and workouts, but the anemia was his fault. However, still with Coach Smith, he had a few healthy months after graduation and ran 3:34. I don't think he ever stayed healthy enough with BTC after that to run any fast times, by his standards.