We did the strat last night on our Normal mode farming run and tbh it didn't look good for heroic. We didn't wipe or anything, but especially the bloods that coincide with the mechanic where you have to hide behind the pillars stayed up a loong time. Maybe shouldn't even try to kill them before that hiding mechanic is over? Or focus them down instead of AoE?
Sorry for hijacking the thread here, heh.
They get a leech buff if they're near the boss, which makes it take longer to kill them.
Whether that makes it worth it to take them out or not is up to your raid composition. If you have enough ranged DPS, you can take them out and burst them down and let melee stay on the boss. However, if you're melee heavy, you'll have to play with keeping them on the boss and melee switching to them or moving them out.
On a Heroic PUG kill yesterday, we took them out and had ranged focus them, and didn't have trouble with that part of the fight.