Double Bard comp is usually a nightmare, at least as melee it has been. At least with Black Mage it is somewhat possible to shut down their capabilities and with trinket(purify) it also cuts down on the sleep problem a bit. However, a well coordinated team running Double Bard can wreck melee teams. I don't know if they are easier for a team with black mages or summoners but this has been my experience. Almost all of my losses are to teams running bards, and the other rare losses are to teams with black mages. Weapon throw is an absolute necessity as melee and should be taken as your first ability, even before trinket.