Don't locks spamming Seed of Corruption do a lot more damage than mages spamming Arcane Explosion?

Wouldn't the ultimate AOE group for Heroics be a prot pally, holy priest, 2X warlocks, and 1X mage?

My thinking in adding the mage is that they would be great for the mage table, AI, and to ensure enough non-seed damage is being done to trigger the other seeds.