I dont really think they need to make them invulnerable. They can just fix some mobs that do stupidly high damage to pets. If they make them invulnerable, great, if not, u can get around those issues somehow. The AI/collision problem makes this build/class unplayable for higher GR. U are competing against a timer and while all other classes/builds can apply all their damage to mobs, we have a good part of our pet army standing still cause they cant reach the target. And playing in a party makes it a LOT worse. At least your dog and garg should go thru everything. Having 20 fetishes surrounding an elite/boss and not letting your dogs/gargs hit its a huge dps problem. Reminds me of the good old times of D2, playing Necro in Lut Gholein, the Maggot Lair.

There's no way u can beat a high GR like this. It's very sad cause WDs in theory, should be THE best class for multiboxing but u rarely see anyone using them. I'm may try the Carnevil build since at least u get a little more control and can have your fetishes go ranged while dogs/gargs tank, tho Blizzard screw up this build too with the leash distance change.