Follow the same style as you did in FFXI,

sleep the mobs and focus on one, problem is sometimes tanks do not number them, so you probably want to hold back the attack first and see which one the tank is focusing.

Unless for speed runs, the team expects u to AOE the whole mobs stacked, its a different style. So probably you need to justify before you enter Wanderer's Palace/ Amdapor Keep, whether is it speed run or normal run.