The siege of Warmind (the part right after you enter the bunker) thralls just comes charging at you, tightly grouped. Don't kill the yellow bar knight at the end. Then after you jump off the bridge. No rocket suicides required. I'm surprise no one mentioned this. The dark beyond you have to worry not to accidentally kill the yellow bar knight because he is mixed in with everyone. Plus the field is wide, whereas siege of Warmind they funnel into the tight corridor.