Calling Lydiard a physiologist is stretching it a bit ;-)
He was a brilliant coach in my mind but not a physiologist.
This is a good example of
A physiologist knows why results happen
A coach gets the results.
There is quite a few good coaches that get good results with a reversed periodisation approach and some of them would surly not be adverse to Lydiards approach.
Olbrecht has obviously a very good science background but judging from his long list of athletes he has worked with, including some of europes top swimmer ( Pieter van den Hoogenband I think one of them) I would assume he focuses more on coaching while still working at the University in Leuven.