yes, this has been asserted many times, although I'm not sure there is a really authoritative statement from a BB about it.
The concept is that the more out of balance the player's skills are, the slower training becomes, which is why I advocate (and am actually training this week) shotblocking training for big men.
NO ONE at this table ordered a rum & Coke
Charles: Penn has some good people
A CT? Really?
Any two will do
Any three for me
Any four will score
Any five are live