I have had Siege Number Three And Siege Number Four. By the Dungeon of Dens - a Goblin Civilization who has been attacking and taking over many of the nearby cities according to visiting officials from my civilization and the Elf civilization.
In the third siege a lone soldier were trapped outside and died fighting. But also a were-gila showed up at the same time and before being killed bit a bunch of beak dogs and a troll - who all died. I was laughing. My were-beast plan had failed totally last time and here is a wild one showing up and killing a ton of the invaders before croaking. The rest of the siege was normal. We took shots at them from slots, visitors got attacked, we added to our zoo, the siege broke.
I tried to turn my were-beast barrack into a tiny airlock. And lined the tunnel to it with stone-traps. And put in cat bait. Idea - next siege, open the outer bridge, let in a few foes at a time, kill them.
Fourth siege - plan fails. The siege starts and two civilians are trapped outside and die. The Trolls came down the tunnels first, set off the traps (all of them), my soldiers killed them, and poured up the tunnel. Turns out my Dwarves, Humans, and Goblins are designed for tunnel fighting. You see, I noticed during training a lot of them were either using bare hands in combat or, the range units, liked to use crossbows when sparring. So I gave the archers secondary melee weapons, and the melee squads extra shields. But in the end they seemed to develop skills in hand-to-hand fighting also. And dodging. Lots of dodging.
So picture if you will, a tunnel, one block in width and height. All my soldiers wearing iron mail or copper breastplates or leather armor, with helms made of bone or shell, a patchwork of anything I can craft. Almost all of them have two shields and the range troops also have melee weapons. One of my Dwarves likes to have a crossbow in each hand and a shield in his left.
They have just butchered two trolls and, in the pitch dark, fall onto the descending goblins who are moving in the darkness in a column, one by one. This is what the Germans called krieg der ratten - face to face, all out, no surrender, blood all over, heads and teeth flying, combat that even amazed me. They kicked and bit and sliced with swords and bashed with maces and stabbed with spears and did a lot of dodging. Two of them went into a trance and became ninja-buzz-saws. By the time squads worked their way up to the entry of the tunnel and they stepped out into the winter sunlight, three out of the 50 or so soldiers were dead. And over thirty of the enemy were dead and the siege was broken.
This is the first time I have ever let my squads charge the enemy without softening them up with bolts or war dogs or something.
And the best part is the mess is out of the way. Nobody will be upset by it.