There's also two orange bars that spawn per pollen buff. Are you buffing to 60x for both rounds (e.g., round one take their health down to 10-20%)? I, personally, don't need all merciless shots to take down the dogs. I use super, one mercifless clip and one energy auto rifle clip in first round and then whatever is available the second round. Of course, when everyone is above 290 it will only take one round. Swords are probably better for the dogs, but I'll wait for Datto to make a video on it (it can also cause the dogs to "jump slide" like the gorgons).