Neal .... That sound's exactly what I found many year's ago with Beardie type's and one that I worked in particular was a line bred dog ( I only keep bitches now) The chap who bred him, kept amongst himself and a small group of friend's alot of the family line from only proven worker's ..... Obviously the sire and dam, but also grand parent's, uncle's and aunty's etc and swore by the type / cross and kept nothing else.
The saying that I was told really hit the nail on the head ..... "They will work with you but not alway's for you"