I'm pretty sure the healer shortages were because of the fights being more of a mitigation check than a healing check. If someone dies to Dominion, it's usually a caster, and it's usually the melee not using Feint. Same with Stomp Dead in P1. I know a lot of healers were sick of being blamed for not healing when they already put up everything they could and the melee missed Feint so someone dies with barely 100 overkill.