I have fostered hundreds of GSDs over the years, and just a couple of Shiloh Shepherds. All of the Shilohs were huge, but in my opinion, a bit stubborn. From my experience they are not nearly as compliant as most GSDs.
We had a GSD/Malamute cross and he was a lot like the Shilohs. He knew lots of commands, but would only cooperate if there was something in it for him!
Yours in GSDs and rescue,
Good Dogs for Good Homes
Virginia German Shepherd Rescue