You can kill off most goblins in smaller clusters.
Always start by getting rid of war drums.
Courtyard
- Second level, sleeping goblins
- Ground level,
poison most in front of doors,
attack from close to portal
clean up those alive by the doors
Main hall
- Get Gut alone, kill her
- Kill the torturers etc in the small rooms
- Kill the remaining goblins in the main hall
Far left (three goblin discussing Wyll)
- Only six goblin will trigger if you initiate combat
Big red goblin
- Will not trigger anything but room
Small room before prison
- Will not trigger anythign else
Basically the only thing that triggers everything at once is if you attack Minthara. I feel a bit stupid for being as specific as ^