People have killed him easily with the rat tail and without. Tail =/= win. I wish people wouldn't think that just because you have six tails you have a surefire win the same way I wish people wouldn't lock certain job spots in. As said before; it can be cleared by any group with some actual thought and preparation. If it's really that bad, maybe wait a few days to a week and collect some better gear? It won't kill you to maybe go out and cap some weapons and collect a few better things then try again with less hassle and headache.