I agree with this set up but it is important to highlight some details:
1. The Druid has to be the first one to get on the stack, otherwise he wont be able to use his Mass Healing Spell.
2. If you are going on a low level character Life Drain protection gear is a must (a.k.a. Bone Fiddle, Ring of Souls, Garlic Necklace, Necklace of the Deep).
3. Even if your team is doing the stacking set up everyone should click on the Bath Tube located north of the room before stacking at south. You will receive 6 water charges that will reduce the damage from Ratmiral's fire waves.
Keep in mind that the boss cannot be close to the Bath Tube in order to use it.