I'm not sure I made it clear. A dog/bitch neutered pre-puberty may grow TALLER than nature intended. Ultimate weight is not believed to be affected. A male neutered pre-puberty may be Smaller in his head, neck and shoulders and chest than nature intended.
If the dog is not purebred then you can't even guess what the final outcome should have been. Even within same sex litters of purebreds of known parentage final growth can vary.