Half of the heroes are useless, or even more. Boost them please, improve their stats, skills, etc. Some of them wont be able to kill hydra, or even broodmother. Please think this over.
They are right, is normal having problems with some heroes agains Dragons, but Broodmother?? that is too much you should play a little more before give ideas, all heroes can win a game solo, all heroes leak in something but have others strong points, there isn't useless heroes, there is only players that don't know how to use a hero.