WHM full Mind, with DL and relic +1: Holy without any kind of buff = 700 damage and can use it 15 times before oom
BLM full Int, with DL and relic +1: Flare with no astral fire buff = 600 damage and 0 MP left (1100 dmg if AF III)
BLM full Int, with DL and relic +1: Blizzard II with Umbral III ~250 damage, spammable
BLM full Int, with DL and relic +1: Fire II with Astral Fire III ~450 damage, usable 3-4 times

Something is clearly wrong with Holy. I don't think the WHM was designed to be the best AoE dps class in the game.