I think he was asking more for pvp purposes. I think with the 3 mages I would go with one frost and 2 33/28(my favorite build) that way when you 3v3 arena you can soft up on guy then POM pyro x2 which would be insanely awesome. I usually use my pom when the enemy is at 50% but you wouldn't even need to wait with 2 mages.

I would pop out hit a scorch, pom pyro x2, fireblast, blink, blastwave, AE( if not dead yet) That would kill about 95% of players, if you don't count Pallys(bubble), mage(iceblock), shammy(grounding totems, but that's why you scorch).

Let me count this up, (estimate) I hit for about 1000 scorch(no-crit), 4000 pom pyro+ arcane power+ icon of the siver crescent, fireblast 1600, BW 1500, AE 900

1000(1800 crit)
4000(6500 crit)(instant)
1600(2500 crit)(instant)
1500(2200 crit)(instant)
900(1400 crit)(instant)
9000 non crit then x2 = 18000 NON-CRIT

if you take out the scorch it's 16000 DMG over 4.5 seconds of global cooldown.

try healing through that.