Caveat: I didn’t read the whole thread.
I always wonder - how much can we reasonably expect of the genes to be displayed in the visual, external part of the dog? Would it not be reasonable to think that some part of the genetics will not be visually evident, and instead be represented only by other parts of the animal?
E.g., maybe your chihuahua x cocker spaniel x pit mix looks 90% pit, 10% chi, and instead has the liver function of a spaniel? (Using extremes to demonstrate a point)
I guess I’m asking, why do we assume genetics will always be on display in the physically evident capsule? Why don’t we assume some genetics will be hidden from us, yet still be present? That would explain why some GSD mixes come back with something like chihuahua, even if they look nothing like a chihuahua.