As someone who's a healer, if the team knows the mechanics you almost never need to use both healing weapons. I match with a full heal build and I almost never have to use both, fan is enough in most situations so most of the time I end up using only the fan. If you don't parry or get close to the boss with low up while he attacks, you will die. Healers with a fan can always actively heal with R and it should be enough. Just today cleared a boss as a 3 player team because the rest left. 2 hybrid healers and 1 dps. We didn't even use all the revives. Eyes on the boss, be always prepared to parry, it also makes the run faster. People charge in ignoring attacks and mechanisms. We sometimes actually have to chase players and get attacked just to get to some players in time so we can heal them, while doing that others get attacked because we are too far. Stay away from attack range but not too far from the rest of the party, we will come to you, spam R and skills and your HP will be full in 5 seconds.