TBH, I think 3 locks is overkill, but it makes leveling easy. If you guys are serious about pve, then I would recomend a mixed group including 2 shamans, lock, mage, priest and druid/paladin. They seem to be the most O.P classes, but with Bradster already have shamans, im sure you could just replace the 2 aforementioned shamans with something of your choice