As a disc with 3 M illgnoth kills. It didn't take me long to figure out the whole raid was smoother when I was holy. (which means we went double holy priest.). I don't think pw:b is alot better then hymn, and it's defo not worth the cost for the rest of the fight.
That being said, you can play disc to a decent level even without alot of haste. So you can always try.
However I find your hps extremely low where-as you guys have like 250k hps each, we usually have 400k each. And I just quick checked every class of ours has only roughly half it's healing coming from the cd during the phase, compared to you where 90% of the healing is all the cooldown. In addition it helps if you use, tranq, dh, htt, that you don't use it at the same time, but drop tranq a second afer hymn.
What intrqiues me most though, is that we did a total of 3 mil hps combined over a short period you guys did 8 mil. Which means you take retarded amounts of dmg from somewhere unintended.
Our kill
https://www.warcraftlogs.com/reports...e=damage-taken
yours:
https://www.warcraftlogs.com/reports...e=damage-taken See how dmg intake is smooth af, compared to yours (which means your timing on killings blobs is extremely off, and we only take half the amount of dmg you do).
To me it looks like a much grander issue then you going disc would fix. But it's worth mentionning you have 3 hunters and 3 mages, all who can immune the debuff.