I was able to do this with a 23 druid and a 23 SK, but it took several tries. It looks like a bug related to the "an imprisoned druid" moving around near the ambush area and causing the ambush mobs to spawn more than intended. My first two attempts I wiped-out badly just like Swight. On the third attempt I was careful to only assist the druid in-place and was only confronted with three or four mobs per ambush.