Agreed with Skel, there's no 'split' in the 7 healers in WOW like Pure/Barrier. The closest there is, is whether they're flagged internally as 'melee or ranged' healer for deciding mechanics. EG on Sludgefist, people are chained together. Snap the chain with distance, die instantly. Melee healers are linked to melee players, ranged healers to ranged players. Other than that, you've got 'cleric style club you with mace' Holy Paladin, 'Vanilla throughput' Holy Priest, 'Do damage to heal premiere' Disc Priest, 'weave between applying HOTs and extending them with physical violence' Mistweaver Monk, 'you have one direct heal, everything else is HOTs' Resto Druid, 'Totems and healing rain and chain heal, oh my' Resto Shaman, and the new kid on the block 'Time magic done really well surprisingly (plus some boring Green spells, they're boring though)' Preservation Evoker. They all work regardless of comp, you don't go 'Ah we have 2 throughput healers, we need a Disc for the shields' because that's not how WOW raid design works. There's no 'you mit this or you die instantly' kind of thing really, it's more 'you take 30% of your HP every second, pump like your life depends on it'. Because it does. Maybe you take certain healers for Mythic, because of their CDs like Aura Mastery or Spirit Link, but that's utility talk, and not to do with the way they deploy their HPS.

Maybe SE could do with less reliance on oneshot raidwides, that you have to Feint Addle Tactician Soil Succor and it STILL drops you to 20% week 1. This tier showed that people aren't so hot at dealing with them...