With the top end gear, it should be very hard to take out five healer spec'd healers.
Not sure what kind of an offense you'd put up.

If it were 5v5 arena, doubt you'd be able to kill anything.
But in a 25v25 (or rated 15v15) you'd make one area of the map extremely hard for the other team to kill your team in.

If you're fresh to 80, I'd stick to AV/IoC (25-mans) and heal, preferably sticking to the largest group of your faction, or staying well back of the action.