In the same vein as not ignoring the repository of coaching knowledge, I’m a big believer in the ‘success leaves clues’ idea; that is, when the majority of those who have been very successful in a particular field have taken broadly similar routes there, that’s a suggestion that said route is, at the very least, worthy of consideration.
In this case, that tends to be lots of volume with some shorter, harder efforts (either POL or PYR). Of course, where this falls down rather is the timed-crunched individual who has very limited time to train in.