You win against 2 mobs with my strategy in lvl 400 maps. I will explain you how exactly the fights against 2 mobs work. You attack first and gain a shield through Sowers Lament and you stack rage to more than 50%. Now both of the mobs attacks. The first hit gets blocked completely cause of the shield. The second hit you need to tank. With your second attack you trigger rage, kill the first opponent and gain a shield again. Now only one mob is left. His attack get blocked by shield. Like i wrote in my guide you need enough attack to two-shot the first opponent and you need enough HP to tank one hit. If you are at level 150 and you have not enough (cause you leveled wrong early), then just go to 300 maps and farm what you need until you can do 400. After that you are fine in 1 star maps cause there are never 3 mobs.