The only concern currently is figuring out how goblins on flying mounts are getting into a fortified tower. They appear to be flying in *through* a carved fortification at the third level of a five level tower. Odd. A melee squad will need to be stationed near there during the next attack just in case. And it was a good break that the marksdwarf squad stationed there was a veteran unit that wore full armor and had gotten some hammer training previously.
They could be moving down diagonally. If I understood another thread correctly, fortifications don't have a "roof" on them, so you'd need to build one to keep things from coming in over the top.
I repelled my first siege today without outside assistance! Usually they show up with a caravan, get chased around by angry guards and then leave (first one on this map showed up, one bolt was fired at them and they left. Such discipline!)
I actually thought it was going to end in disaster as I'd taken and melted down all the metal crossbows that the rangers were showing up with and forgotten to make new crossbows for them. So the goblin siege passed through my shooting range completely un-shot. The captain of the guard actually has an artifact crossbow, but he didn't feel like showing up to the fortifications
They got down to my trade depot, but the entryway had effectively split up the various squads, so I said fuck it and unlocked the doors before the trolls got to them. My two(!) swordmasters then rushed out and carved a bloody swathe up across the trade depot and up the halls. Neither got injured, though the marksdwarves that showed up and began wrestling got a little beat up. I need to make them some crossbows and set up a range. I'm building a sentry tower that overlooks the looping access path to my fort so I think putting a small range on top would do well at keeping dwarves up there to shoot ambushes and the like.
Jerk ass goblins did set my dog breeding program back a generation though. All those gigantic, muscular puppies got shot up. Thankfully one of the remaining female dogs gave birth to a male puppy with incredible muscles(very muscular? I'll have to look when I get a chance later) and just gigantic overall. I wish the wiki had more information on these stats and what they do. Not sure if I should try to breed for fat, or what the cap is for muscles/size. I haven't seen anything over gigantic, but I also haven't seen any kind of "small" tag.