One of the best places I have found to Level with no adds. If you go into the tunnels from WW side, you will come up to a juntion where if you go straight you go to LOIO but going left or right leads to a cave with three of these Brutes.
They are far apart enough to single pull by simply walking up to them and smacking them. Once you clear the room, turn around run to the other end of the juntion and hit three more. By the time you finish. the previous cave will repop and the fun will begin again. I made 3 Levels alone there and with the various gems and loot it is also very profitable.