PuGs oneshot coven since 3-4 weeks. At least the pugs I join. Week 1 took 3 days to kill it. But now the DPS is so high, that you just lust at pull and only get 3 phases max. Also the storm nerf was huge to pugs. You also can compensate some deaths. A group that kills varimathras now usually oneshots coven. Bringing out necrotic seems way harder than dodging some ghosts.
edit: got your first post. Or maybe we kill it, because we play it clean? CCing adds and using a personal if we have to move into the storm during army? yes, you dont have to die to the army only because its overlapping with the storm. You survive some hits. Do you CC/slow the army? You blame others, but what do you bring to the raid?