I disagree.
Historically-speaking, the best dogs in history 99% come from breeders exclusively--or from people who bred two dogs together purchased directly from breeders exclusively.
The rare dogman who can BOTH show dogs exceptionally well,
and breed dogs exceptionally well, will
never sell you his best dogs: he will keep them for himself.
You are almost guaranteed to get a "less than" dog from a competitive breeder/dogman,
whose own money is riding on what he keeps
The legit breeder doesn't need to have conditioning experience to know what to look for in a dog, nor especially on how to reliably and consistently produce good dogs.
More importantly, a legit breeder (aside from having THE most experience breeding good dogs) will also
sell you the best dogs he has, for the right price, because he wants his best stuff to get shown
Jack