Holy Nerf is a Net Buff

[nyttyn]

Assumptions: 9 mobs attacked, with them staying alive long enough for 7 holy casts (which is 6 holy + 1 Aero III), mobs stay alive long enough for full duration of Aero III (which is 24 seconds, not unreasonable).

Old WHM AoE: Holy(200 * 9) * 7 = 12600 Potency
New WHM AoE (Holy((200 + 180 + 160 + 140 + 120 + (100 * 4)) * 6) + Assize(300 * 9) + Aero III(370 * 9)) = 13230 Potency

Obviously you can napkin math this out with however many mobs or for however many casts but new WHM AoE wins out over old WHM AoE pretty clearly.

Edit: Even at 20 mobs it's like 28000 vs 27200 which is still a pretty small nerf, and we're never going to be able to fight 20 mobs at once ever again with square enix's new dungeon layout. And for a 20 mob pull, if you can get out 7 holy casts, then I salute you sir.