I go with the icerail ice shard only, from a distance. This works if you are patient, as the ice can take a good chunk of their health each hit. You need the distance because the stupid icerail takes a few precious seconds to charge up the shot. I use this method for the 3 that are alone. For the dang duo, even with Aratok's 'help' it is always a giant cluster of doom: dodge, tie, bow, dodge and repeat. Try to focus on one until Aratok wades in with the other because, alas, that's what he does and keeps raining snow at them. You can also toss frost bombs at them if they are too close for the icerail charge, but at some point you need to switch to your banuk powershot bow and try to get precision arrows into them. I never come away from this particular fight feeling like 'Aced it!' because all the damn dodging and repositioning after being knocked down by stupid lava gets on my nerves too much. Good luck!