Sorry Doug, not saying you are wrong.
But, I do not believe that 2.5 hours is needed. I do feel that is excessive, balance in life is a good thing. Take running seriously, when you are away from practice enjoy that time as well.
You said it above, if you want to improve your program, run more. That is true, but no HS kid is running 2.5 hours a day with the exception of Gerry Lindgren maybe. If you are running 70mpw that is 10 hours a week at 7:00 per mile, how much ancillary work is necessary? Core is somewhat over done in many cases, you will work the core muscles involved in running while you are running. So, cut the core work in half, 15 minutes per day, I used to do 12 minutes. Do some running related form drills a couple of days per week, some general strength and mobility work. Add in a warm up and anywhere from 1 hour (easy day) to two hours max on a hard or long day. Touch on different areas each day, develop complete runners.
Not saying either way is better, I chose not to go in the excessive direction, was probably not competing on the highest level because of it. But, I wanted to see my athletes have a good experience and continue with the sport and had many continue collegiately and beyond.
Just my half a cents worth.