'Mixed' often means you don't know all of the breeds involved, but I have a friend with a half-border collie, half-Australian shepherd. Someone I see on dog walks has a half-border collie, half-Golden (one green eye; one blue).
I give an enthusiastic thumbs up to those two mixes.
In the case of KNPV, they usually do, for at least two or three generations. They're breeding dogs for courage in working ability, which is more about temperament than it is appearance. There are a number of tests in KNPV PH1 trials that involve working through pain (that the dog knows is coming), gunfire, judgment under intense duress, and commitment to a command despite agitated distraction. Then there is endurance over a trial that takes two days to complete, from obedience, to athletics, to tracking, to object guard, to bite work. A KNPV PH1 title is an achievement exerting enormous influence upon the breeding program there.
My point is not about KNPV as much as it is about the original purposes of dog breeds. They were for work. We should never forget that nor omit it from our qualification for outstanding individual attributes. In that respect, the AKC with its focus upon appearance has done enormous damage.