I tested 1 Paladin 3 Mage 1 Priest

Yes it's ok for AOE but the main problem I did encounter with the AOE spec is that as multiboxer i wasn't able to manage a frost spec correctly with the 3 mage to make big Pull like you plan to do.

I ended with 3 Fire Mage + 1 Holy Priest, and it was more easy and efficient. The pull were smaller, but I was able to chain much better and safier.

in 10 Sec 3 frost mages will make :
1 Nova each one, 1 Cone of Cold and 3 Arcane Explosion

in 10 Sec 3 Fire Mage will make :
1 Flamestryke, 1 Blast Wave, and 3 Arcane Explosion and it burn on crit

at the End Fire got a bigger burst for quick AOE
Flamestryke will have always +25% Crit chance and Blastwave +10% with Talents
And Fire spell got 10% Chance to Stun mobs, this help a lot

In your Team you have Warlock if i'm right his AOE have chance to stun aswell, so for me Fire is a good choice with your Team.