Great story, Kenjigreat, but have you ever played a healer? Never ever calculate healer's power via his health. Tionese level geared healer has way less than 18k HP and is perfectly suited for any HM (LI included). Even HM Ops (not EC, of course) are doable with 15k HP healers.
I wouldn't want to be in a solid FP with a 15k healer. even my comps could probably heal better. Same goes for 17-18k tanks, I'm currently a sentinel with 18k no buffs if I'm not getting far in a FP and the tanks only got 17k then that's probably why. When the tanks not good enough to hold the agro or dies the DPS is usually first to get it.