They don't. IPO is a sport, it has established rules and standards. Without participating in IPO the dog cannot be qualified as a GSD for breeding. Here, you see, it is Germany who dictates. And it doesn't matter which one of two breeding lines your dog represents, you still have to prove that your dog is capable mentally and physically to pass those tests. No wonder why people with money prefer imports from established kennels in Germany - they are the dogs of dream. They can be Police dogs and control the crowd, and they can be service dogs, anything you want - depends on training, no behavioral issues whatsoever. And the German rules are getting harder, if you mind yourself a quality breeder - you should know that for US and any other breederis required a with DNA test, all existing in the world breeding lines should be traced back to Germany with DNA test: Sirius Dog
Wembley, you are preaching to the choir, though I'm not sure just which choir. Sometimes the best way to learn is to listen.