I start on the left side (that the laft side as you are facing the area that Crota spawns). I'll run in and draw the attention of the first wizard. I'll then retreat to the boomer tower and pick her off with an Icebreaker. Repeat the same steps for the right side. I stay on the right side for the shieker and equip my ghorn and make sure I've got full ammo for it (shriekers won't spawn until it says the Deathsinger has begun her song). I'll run in, past the mobs, and take a shot at the shrieker. Here's the tricky part. If you leave too quickly, the shrieker will close back up and the wolfpack rounds won't finish it off, so you have to make sure it's dead before you run away. Watch out for the mobs. You'll know it's dead because the giant purple death orbs will start to seek you out. At that point, you run to the other side and do the same thing with the left shrieker. When it's dead, move back to the right side (death orbs will be gone by this point) and attack the deathsinger from that side. There are WAY less mobs to deal with. I'll use the remaining 5 rounds from Ghorn to take care of her and then will retreat back to the boomer towers to clear out the remaining mobs. Acolytes will continue to replenish their numbers as long as Knights are still alive, so focus on the knights first. Otherwise its a waste of ammo.