The way I like to do it if i'm boxing a druid, is just zone in, kill the named on the way to the pit, drop into the pit and down those, then kill the few around the castle. Abuse invis and track essentially. If you're solo, maybe just go for the ones around the castle (careful for mana drain mobs, let your pet do the work) and drop up/down in the water thing to the pit to snipe a few of those.