My own experience is exactly the opposite.
The truth is, any bozo can "make a cross" with two linebred dogs he purchased from someone else's lifetime commitment to keeping a pure line competitive. That is why every beginner on earth "crosses" dogs, while most of the truly good, longstanding dogmen on earth are always busy maintaining a pure family bloodline ... which should be clue enough for a smart dogman to figure out, ultimately, what the best way to go is to get consistent results
Further, even though I recognize that there are dozens of great outcrossed matchdogs, mostly because that is what most folks breed-up (and which, by the way, even when produced by good dogman are typically matched precisely because they're not as valuable as the good family-bred dogs that are kept at home for breeding), I have seldom seen any outcross dogs I've sold that can whip the best of the inbred dogs I've kept at home.
As proof for this, when used as box dogs there are very few outcross individuals that have achieved the same success as family-bred individuals such as Gr Ch Buck (7xW), Gr Ch Zebo (7xW), Gr Ch Tornado (10xW), Gr Ch Happy Jack (5xW), Gr Ch Sir Dog (7xW), etc.
And, finally, even the best and most important outcrossed performance dogs, like Gr Ch Yellow (6xW), still required 2 inbred dogs to produce them ... and the very first thing a good dogman does, when he produced a badass outcross like Yellow, is to begin a family-breeding program around them
So you might want to re-think the value of family breeding
Jack