Some interesting thoughts – if what you say is true, then every GSD pup from a working line will pass as a police dog, not sure where the facts come from that a non-working line boxer can make it but this would be an exception, a boxer is by nature a working dog. Then again, pups from a so called working line do not always meet expectations.
Working dogs does not necessarily mean IPO or Shutzhund, I’m not sure if our discussion is on this.
Police are favoring the Malinois over the GSD because they are more eager to work and learn faster – a Malinois would not be a good choice for a novice dog owner – not quite the right “personality” because they are the way they are, not because they are from a working dog line.
Boxers should be worked, they need it and they need to be kept mentally and physically occupied and it’s always good to have a dog that listens and behaves when needed.
Working dogs is sport, the dogs enjoy it and it’s good to have a controlled dog. It’s also used as a selling point, a dog with tiles sells pups at a higher price.
My view is that a trainer / helper is the key to get the most out of a working dog breed – these can also be pups from a non or limited “working dog” line