Interesting. Didn't know that. Begs the question though why nobody kills them quickly.
Because they're idiots?
When I tank the boss with the 2 dogs in Mandalorian Raiders, I mark one of the dogs with target and tell the DPS to go for target, other dog, boss. Only the boss is tauntable anyway and the boss has aggro switching, if the tank keeps them busy as much as they can and uses their single-target taunt (they won't have AOE taunt yet) on cooldown then they're doing their job.