Come on, DD. 10 minutes per dog, and look at the benefit.
I can believe that dogs recognize other breeds, and their own, I see it time and time again. I think Shadow and Roo would probably get on and they could start up a 'let's hate GSDs' club. LOL. My hubby helped me a bit when I was showing but obedience doesn't interest him. My sister is lucky, her hubby supports her every inch of the way where obedience and tracking is concerned. I think it could be tricky showing Roo, it's usually crowded and not a good scene for a reactive young wannabe alpha dog. Wouldn't be so bad if he was into sly looks and sneaky attempts at attacking but no, it's all hackles up and the most ferocious growling. Must make any other male dog want to take him down a peg or two.