Having swarms of dumb goblins gives you opportunities for efficiencies as well. Take away all of the fancy toys from the vast majority of them - no grenades, no magic arrows, no magic of any kind. Just give them a scimitar or a shortbow (or both). Make their AI: run at the closest enemy to me and attack. Anything you can do to make their AI dead simple and fast.
So you want Larian to make the fight boring by creating BG1 quality enemies in a turn-based game?