So long as Sauron has at least 3 Wounds remaining, a Barad-dûr Army can never count as being Broken. Should Sauron have 2 or fewer Wounds remaining, a Barad-dûr Army will Break as normal. However, should Sauron ever be removed as a casualty, a Barad-dûr Army will immediately count as being Broken.
Victory is at hand
So long as Sauron is alive and on the battlefield, friendly Orc models gain a +1 bonus to any Courage Tests they are required to take.