I went and had a play around in there the other day - 80 warrior tanking and took 4 shamans when they were 78ish. Cleared upto and downed opera (big bad wolf) then got bored and gave up.

Best way to do moroes is to aoe tank the lot of them - kill the shadow priest, kill the holy priest - then just nuke the rest.. making sure you keep the aoe healing up because of the garrottes. Decent armor on the shamans will stop them getting spanked when your tank is blinded aswell.