I'm below-average talent and train somewhat similarly to this (I've posted about this here before), although not all "easy" mileage, but I don't cross train:
(context: never broke 16:00 5 km, but did run a 15:09 3 mile once when i was training on 80 km per week, before the mileage broke me,16:22 in xc)
Last year, I was running three times per week (T, Th, S/Su).
Two days of light progression running, tempoing/hammering an out-and-back course for 6 km per day.
The third day, I would go to the track and run a time trial or 400/300/200/150 m repeats (total volume 7 km).
So, 6+6+7 = 19 km, ~ 12 miles per week:
I raced 5 km a few times, running 17:20 at best (twice) and ~17:40 two or three other times. I also ran solo time trials of 600 m in 1:34 (2:06 800 m pace) and 1000 m in 2:54 (4:40/mi).