Good question Jed!
Tend to do a mixture here with a little aussie flavour thrown in with the complex system.
Trained with Cook for a year and had the chance to run with Abdi Bile (1500m World Champion 1987) and his system was very similar to Coe's but the issue was being able to stay injury free. Most people don't know that prior to Abdi winning the WC he was injured from December to March and didn't run at all.
Long hill repeats, progressive runs, alternations 30/40's and with added dynamic drills, bounding, and strength training made us all very fit. This works well when coaching juniors.
Training with 83 WC Deek his system was all about consistency. Every week was nearly the same. Monday/Friday recovery, Tuesday and Thursdays fast efforts with float recoveries, Wednesday progressive, Saturday hitting every hill hard over 10miles and then the tough long runs on Sunday over 18-22 miles of hills.
Nothing is new out there it is find what an athlete can tolerate and be able to come back the next day.
I think there is something in cross training as here in Australia triathlon are big. One 17 year old boy a few years ago ran 8:08 for 3k and he probably ran about 30 miles per week. Swimming and cycling are great tools for recovery and enhancing aerobic development without the pounding of running.
So who is better Igoli or Lydiard i have no idea the perfect training system is the one that works for the athlete that allows them to win that gold medal i guess.