this is a brilliant post.
basically response to stimulus is individual.
the workout is designed for maximum response, adaptation.
some guys get the response with less mileage.
but if you just look at the quality, a guy like lagat or spivey will be similar to everybody else, at world class.
a coe would have really done a lot more than advertised.. with the quality being through the roof.
at the end of the day, with middle distance, you need the speed and the max oxygen uptake which is why they call it middle distance,
if the speed requires 10x400 for one guy and 5 x 400 m for the other guy, to get the adaptation so be it.
whatever the cells need to get the response.
therefore training is individual specific.
with that said, 35 miles per week for 1500 and 5000 k is BS
but you can do 800 to 1500 on a minimum of 50 miles per week with half quality.
20 miles quality per week is a lot.