I got up to crota with four 32's and two 31's. Myself a 31. The maze is still quite easy. We used to two groups of 3 strat. Then for bridge we used the technique of getting one across and having a warlock self revive on the side you start at. He then kills the ogres. Deathsinger took a few tries but was done. Crota we struggled with and eventually all left. I have since seen a decent crota video though using a method where everyone runs to the centre just infront of the glass where deathsinger spawns. That looks effective.