It's a bit late in the Xpac to bring this up, but for anyone looking to try and get these done before the pre-patch, I found this set of videos.
CM Challenge Modes
Shrykos, Keskein, Zen, Mandog and myself eked out a bronze rating for Auchindoun. They are true to their name, for sure. I'm hoping to work on these a bit sooner in Legion, and not be behind the ball.