When you have a small guild and a small healing force, you tend to know people’s strengths and weaknesses very well. This sometimes leads to unconventional healing assignments based on what the player is best-suited for, not what the class is best-suited for.
Pally A has trouble changing targets and changing his focus. To use his abilities to the raid’s advantage, he needs simple instructions. “Heal Tank 1 and beacon Tank 3.” As long as he has a job like that, he puts out spectacular numbers and the tanks don’t die. But don’t ask him to “spot heal”, throw out a crazy cooldown on another raid member, or decurse.
Pally B has somewhat of a “hero complex.” He must be “saving” this one or that one from their own stupidity when he’s supposed to be tank healing instead of simply focusing on his assignment, sometimes to the detriment of his assignment, and leaving the raid healer with little to do. Eventually I just gave up and put him on raid healing. Though a pally, he’s an excellent raid healer, probably better than some AOE healers out there. It just suits his temperament.
Shaman A rarely uses Chain Heal when assigned to raid healing, preferring to use LHW. It’s totally fine to put him on tank healing. In fact, he excels at it.
Sure, I could give Pally B a lecture on sticking to his assignment, or Pally A lessons on target switching (and I do). It would make them better players overall if they were more flexible. But in a raid situation, if we want to succeed, I tend to assign based on the strengths of the player, regardless of what the class is supposed to be good at.
How do you do your healing assignments?