I have come to find that this is one of the most difficult levels to this game.  Up to this point, there has only been one hard boss to defeat.  After several failed attempts and going at it single player instead of double player, we figured out the clue to it.  Though the trolls at the dwarven base are the hardest.  We've tried the combination of Dwarf/Ranger and Dwarf/Elf, and whether played alone or as multiplayer, we cannot figure out the jist of how to beat these two big guys.

Any suggestions...any one??