Ok, I admit I didn't go against +3 mob for a long time, because that taught me enough to not bother with them. I don't say it can't be done, it's just not worth it. I play on rested xp almost all the time, so maybe I have that luxury, however ... how it goes:
-2 mobs I can kill 2 in row and I have enough mana to kill 3rd if needed
even mobs I can kill 2 in row, but if I got add during second pull, I might run low on mana
+2 mobs I can kill one in row, because then I'll have half mana and maybe even little below, with bad resist streak, add can be very bad
+3 mobs can't be fought with standard tactics, because they resist a lot (usually things like pulling frostbolt or FN) and I am forced to IAM (low DPM), and although I still win, I end the fight with half life and quarter mana. Considering inability to handle potential adds (well ... sheep (if it isn't resisted) and evocation (once per 10 minutes) is always possible :/ ) and danger while resting (from both wandering mobs and players) is just not feasible for me
-2 mobs I can kill 2 in row and I have enough mana to kill 3rd if needed
even mobs I can kill 2 in row, but if I got add during second pull, I might run low on mana
+2 mobs I can kill one in row, because then I'll have half mana and maybe even little below, with bad resist streak, add can be very bad
+3 mobs can't be fought with standard tactics, because they resist a lot (usually things like pulling frostbolt or FN) and I am forced to IAM (low DPM), and although I still win, I end the fight with half life and quarter mana. Considering inability to handle potential adds (well ... sheep (if it isn't resisted) and evocation (once per 10 minutes) is always possible :/ ) and danger while resting (from both wandering mobs and players) is just not feasible for me