I plan to use these materials briefly while going through Chads videos (along with his quizzes) to cement concepts and address topics that need more attention.
After the "learning" phase, I plan to use the GC Destroyer and OC Odyssey as extra practice to bring up certain weak points found while doing DAT Destroyer.
Your main focus is learning each topic found on Destroyer. These extra materials allow you to pinpoint specific topics for extra practice.
I haven't even started my studies though, so if anyone else has an input I'm sure it'd be appreciated.