Thank you all for the advice and tips

I'm not on 360, but a little helpful advice. I found a sort of God spot in the bones on the right of the map. Up near the end on the right where the ground goes up theres a small spot that is partially hidden on the ground. You can still be hit by projectiles but not enough to bring your health down before it starts to regenerate. As for the ground forces, so far they haven't been able to find me when I use the spot. Hopefully this will help you.

Hey man, I not on 360 either, but if you have a decent sniper you can also stand in front of the green circle that hurts you and snipe the Wizards. When you start to see red behind you, it's the shielded boomer knight. Just run back past him and immediately to the right in the next room is a cave. Go through the cave and come out at the bottom. The shielded knight should be aggro at the top entrance. Shoot at him and he will come down toward you. Just run back up through the cave and out to top of the hall. Stop in front of the green circle and snipe some more. The Wizards that you don't kill right away will move. Two go toward the back, and the other two will move to the front right and left. Just move to the sides of the circle to get angles on the ones you can't see. Don't take too long at the circle because the shielded boomer knight will come back. I will usually stay and snipe for 5 to 10 seconds and run back to the cave, go back to the bottom entrance and re-aggro the knight. This way the knight doesn't get back into position and hit you with his bombs. It's a pretty easy way to solo that part of the mission, especially once you learn where the Wizards move to. Good luck!

Not on 360, or I'd help. There is a cave/room I the back left (from the starting point) that's pretty safe. You can get in cover from the boomers and wizards, and all the thrall funnel in from one opening.