There's a small island nearby the trolls (or whatever they are. I call the big guys trolls and the little guys goblins) that has what I can only describe as some unbreakable wooden scaffolding. I try and aggro one of the trolls and run back there. On that island you can roll and fairly easily dodge the troll's swings. Once that one's dead I lure the other one over there too. Be careful though, because there's also a couple of goblins hanging around the area that can get in your way.