Yeah. Banshee is widely considered to be the worst hero. Black Wing isn't very good either, and Unicorgi used to be good, but now is pretty mediocre.
Any team with Moon + Dungeon Man will make the fight much easier. Dust Devil will more than double your damage, so Moon+DM+Dust+any damage dealers should win it for you. If you still have trouble, include Medusa, and make sure she enters the final fight overcharged (by not using white skills much in the first two rounds). That goes for every campaign level, unless it has crabs. In that case, bring a tank along (preferably Brozerker with the bodyguard skin, or Bulwark Angel).