Mounds alternate popping north and south, Can Nuke and melee them. Did not notice any additional damage from meleeing them.
Best to pull all the mellee back and go to range DPS once the pattern mobs start so you get less swords. From then on its just a slow and steady down killing mounds, replicated weapon adds, patterns and nuking named.
Had heard hps lock and you need multiple dumps of the water and carts but did not see that when we did it.