I find this conversation interesting because I did my first duties with a 2nd healer over the weekend and I thought, "Now what?" As a BRD, I always noticed that the tanks would say, "do you want to MT or OT?", but you don't know who is MH and who is OH. Should I be healing the tanks? Should one of us be healing the MT while the other the OT? Should one be taking care of the DPS and the other the tanks? What about when extra DPS is needed? Who should be slamming on the needles while the other continues to heal? If one is a SCH and the other is WHM, there are so many opportunities to exploit each other's strengths if tactic is applied. When you drop into any of these duties and no one has worked together before, a small bit of communication can help quell the confusion for sure. Somehow, I was able to work through Chimera, Bowl of Embers, and the Hydra; but I think it would have been better had we communicated in the beginning.