I own all 3 pets and what I found is this. Nekro is an all out defensive pet but makes up for it by having the highest area attack on passive. Unfortunately, I've had bosses one shot crit through the shield and killed me before. SNS is the ultimate all out damage and survive mob pet. If there's more than one of these in a party, prepare for fastest healing and highest wide area attack. Unfortunately it leaves you wide open to one shots not only from bosses but mobs as well. Also, when pet is in cool down, you will find it hard to survive unless you're a mage with shield or a tank. The pools also go all over the place. Best used when there's a nekro in party for protection as a rogue.
Munch mouth at first I didn't think much of him, but I think I underestimated this pet. Never mind all the things it can do, nekro and sns does those better. It's actually the crit nerf that you're after. With the armor bonus and passive armor added in, even when a boss red zones me and I'm inside, AA doesn't allow the boss to crit and I actually survive! I'm finding that this is the best pet for survival when you get to time the AA. It's like you get to constantly use a chest splitter on a boss and it lasts for a few seconds even without a warrior!
As a warrior, depends if you want to full tank and protect your team. MM is a good option that many have underestimated it. If I didn't have any Arcane pet, get nekro as its the cheapest and overall the best and most balanced pet. If you can afford either SNS or a MM, I personally would get SNS on a tank for max out damage. You are able to shield team and CS/Axe to anti crit. If I were a mage SNS as well since shielding can protect from one hits. As a rogue, with a team of players running with nekros, I still find MM keeps me alive better than SNS.
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