According to an interview with Kevin Lyman the "3rd stage will be running all the way up until Slayer". If the same system of alternating bands from stage to stage sticks around it seems like Anthrax might overlap with Motorhead.
10/17 - Machine Head/Battlecross
10/31 - Killswitch Engage
11/28 - Slayer/Exodus/Suicidal Tendencies