Two melee fighters are at a bit of a disadvantage against ranged opponents, particularly mages. If you can switch one to a bow or crossbow, that would let you start hitting them sooner, which will interfere with their attacks. The act 1 summoning doll can equip a crossbow, though even leveled up he is not very tough (note: summoning doll upgrade skills can not be unlearned).
Other than that, if you approach slowly you should hopefully be able to take on a couple at a time. If you run into a group, you could withdraw, and those that followed you should spread out a bit, and you might be able to turn and fight the closest, while the others were still catching up.
There are individual and party based Cure Disease spells, which have lower mana requirements than the offensive version (learn from Annabelle in the BF of acts 3-5, or Elder Ansukar on the summoning level in act 4). As warriors your characters probably do not have a lot of mana, but they may still be able to counter the spells of one or two mages. Even if you can just buy yourself a few more seconds or so to attack and defend at full strength, it might make a significant difference.
There is no use for the permanent rocks. The Larians may have been planning to do something with them that didn't get implemented, or they could just be a red herring. You could always enter and exit the BF repeatedly, checking the BF merchants for holy water, to make permanent alchemy potions.
