General notes on goblin killing:

---Pick goblins off in sections. Save Dror Ragzlin (spell?) for last (all others turn hostile once he is dead).

---Destroy the drums. This will start the fight if they see you, but for many of the areas, you can sneak and destroy the drums without getting seen. Do not stand around a destroyed drum - if a goblin sees you near it, they will accuse you and failed 'diplomacy' rolls will start the fights anyway.

---Smokepowder barrels are your friend. Two of them going off next to a boss will kill or nearly kill any of the three goblin bosses. You can place them while the bosses are still non-hostile and use them later. Note: Smokepowder barrels do not work properly when they are broken - you have to hit intact barrels with flame to get the most bang for the buck. Luckily, there's a lot of smokepowder in the goblin sanctum, you just have to figure out how to get it...

---Avoid crowd scenes and look for exploits. There are programmed ways for many of the goblin encounters to either isolate the heavy hitters or kill off a lot of the scrubs at once.

The Wood Woad / Mephit fight: Somewhat spoilerish, so:
There's a back way into that area if you have enough Misty Steps or really good jump distances. It allows you to get your party on top of the plateau before starting the fight, which allows you to rain he** from above without worrying about your party members. Fly the camera around to find it.