With that team, you aren't going to be casting flamestrike, blizzard, or rain of fire. you would have to mouse target and what not. But you could go for improved arcane explosion, and I'm not sure if locks have improved helfire. But if you really want to aoe some groups down I see your pulls going like this. If you just want to aoe go for a 33/28 build for the mages.

1. avenger shiled
2. consecrate while mages and locks dps first target(so you can build threat).
3. Then hellfire and spam arcane explosion(blastwave when up).
4. you will probably just have to heal the pally cause you will have enough threat build up but in case someone aoes you got holy nova!

that will be some sick aoe.