In my last fortress, must missed, fps dead Spiralchants, when the system hadn't been sabotaged by one of the many ghosts hovering around the place, the goblins died in three steps.
1. Short tunnel, lined with doors, open to the tundra sky (for some reason). Base immediately after the door at the end and only one war dog, one cage trap and one pressure plate. The pressure plate opens the aforementioned doors. Water comes out. Everyone freezes, short hallway gets sealed, pressure plate triggerer gets in cage trap.
2. Goblins now path the long way, through the maze. Maze is on a hill, outside of maze is a row of cave-in traps, underneath a little chamber, accessible from the outside but not connected to the base except via some fortifications. Behind the fortifications is a pump stack leading to the aquifer. Goblins enter walkway, I set off cave-ins at my discretion timing for maximum damage. Goblins get killed, knocked down into the little chamber. (Due to frozen booze and FB extract mess, they get hit with boiling everything as well, can't really tell if FB syndrome takes hold though
When there are a couple in there I let the water out and either freeze or drown them, depending if they get washed out into the sunlight or or sealed in the bubble of ice that exits into the sunlight (and thus drowned).
3. Next few goblins fill up a little cave-trap hallway, just to keep the arena stocked.
Who ever gets through that meets the military. that pretty much wraps up anything