With the rogues, you could burst one, hit preparation and burst another.
At that point, its 5 on 3, but you're out of cooldowns which means you're very vulnerable as a rogue.

If its 4 rogues and a healer, you might be in good shape 5 on 3, especially if the two you took our were DPS toons. With all poisons on all targets (Fan of Knives x4), you could be in decent shape.

I'm messing around with a macro for focus, but going Round Robin and FTL on it, via InnerSpace. So press 1 has Toon A set the current target to their Focus. Press 2 has Toon B set the current target to their Focus etc. Mine is for Cyclone to multiple targets at once, but this could work for melee targeting too... not sure how well though.

You could possibly go with a macro to target your focus, and then spam Interact along with an interrupt click sequence featuring Kick, something for combo points and then Kidney Shot... with two rogues on each healer.

Not really sure how viable this would be, but it could be fun.