4x DKs and a disc heals or pally heals

[Feehza]

If you're doing battlegrounds or arena, a Paladin is far less squishy.

You have Divine Shield, Aura Mastery/Concentration Aura, and your 'Big Button' with all other cooldowns.
Your healer is wearing Plate and carrying a Shield, for the highest melee mitigation too.

I've found the Paladin puts out very impressive throughput onto one target at a time... so no matter who they focus on, it is easy to set that toon as your focus and have massive heals directed that way.
The AoE healing is not nearly as good as other classes.

This!
I tried Disc and 4xDKs in Cata. And it was squishy as hell. Often my priest died within the first 5 seconds.

[luxlunae]

This!
I tried Disc and 4xDKs in Cata. And it was squishy as hell. Often my priest died within the first 5 seconds.

He said PVE ONLY in large caps.