Arena Tactic - 5v5

We had some time over the weekend to run some 5v5 arena action. I was elected the target caller since I know every class inside & out - gosh, I'm such a nerd.

So we get in there and I quickly realize calling targets in 5v5 is much more difficult than 2v2 & 3v3. We went 3 losses and I decided to make a change. I employed a tactic that we used back in Ultima Online when battles easily ended up in 5 vs. 5 or more.

We had 4 DPS w/ 1 Paladin healer. I had the Rogue & Shadow Priest go into their own vent channel to call their own targets, while me and the other Frost Mage stayed in the channel with the healer for our target calling. The premise behind this is that it's easier to control 2 players than it is 5. Well as soon as we employed this tactic we won 8 in a row before loosing. At that time our Paladin had to log, so we called it a night.

I'm anxious to use this tactic again since it worked out well. Does anyone out there have any other arena tips, preferably 5v5?