AOE tanking for casters doesn’t work. Why are we AOE tanking casters in the first place? They don’t follow your pet around like melee attackers. They attack from afar and they are squishy. If you know you’ll be going on a quest that requires you to kill casters like the reputation grinds for Scryer or Aldor, then bring your cat, raptop, devilsuar, or any ferocity pet.
Take on the casters one at a time. Your cat will cause them to bleed to death. Your cat will level. You will be happy killing them faster than you did with your gorilla. Now you can feed your fish you got from fishing to your kitty too.