At my first fortress, Mafollimul, or "Chambergolds", I had a pair of highly skilled military dwarves. Unfortunately, Edėm (Adept Swordsdwarf) damaged the spine of nearly everyone he sparred with, including Mebzuth (Legendary Marksdwarf). The only ones left sparring were the Captain of the Guard, who I had put in the fortress guard for some reason, and a macedwarf whose name I forget. Anyway, Edėm, Mebzuth, and that... macedwarf... guy had made it through several sieges unharmed. Mebzuth would fire a stream of crossbow bolts into the goblin leader, Edėm would run past him and take out the back row, and the macedwarf would throw up everywhere due to cave adaptation.
One of my early ambushes, before the recruitment of the previously mentioned macedwarf happened like this: all of my dwarves were on the red sand roof of the fortress performing various tasks, when suddenly goblins appeared out of nowhere and started shooting at them. They ran back and forth for a pretty long while, dodging the arrows until Edėm and Mebzuth finally managed to get out there and clean out all of the invaders. The amazing/funny part? None of the civilians were wounded, except for one peasant who got shot in the arm, and a stray war dog who got killed after the two arrived at the scene.
Later, I had assigned a lot of my dwarves to hunting (including Edėm so no more spines would be broken, hence why he ended up only being an adept in the end). One had a habit of losing his breath and giving up before he could kill anything. This turned out to be his downfall, as he was later knocked unconscious by a giant leopard. I thought he was going to die when a crossbow bolt killed the leopard from offscreen. I looked, and sure enough, it was Mebzuth, who immediately fled the scene shortly before a dwarf ran all the way across the sandy landscape to bring the wounded dwarf a bucket of water, and then another one came to retrieve the dwarf but not the bucket. Unfortunately, since this was an old but still 3-D version, the hunter kept passing out in his bed, eventually dehydrating.
Then came the second-to-last siege at Mafollimul. The siege was coming from the south, so I had the entire military (all three of them) positioned on the roof. They wiped out the first wave just fine, but that's when things went wrong. Mebzuth, possibly angry at Edėm for breaking his spine and then taking all the glory despite being less skilled, left. By the time I looked back at Edėm, Mebzuth was missing. As I looked for Mebzuth, it started to rain. Then I found him, outside, at the trade depot, enjoying a drink. In the rain.
Just before I got to order the other two to retreat for the moment, the macedwarf charged into the second goblin wave. Edėm went in to help him, but he got surrounded. The two were soon shot and killed by the third wave, ending a six year legacy of spine-breaking. Shortly after, the goblins found Mebzuth and killed him while he was still drinking. Then the goblins just... left. Like they knew what would happen to my fortress next. Sure enough, all of my dwarves were so depressed that their favorite dwarf superhero show had just aired its last episode that many of them started to go insane. Carnage ensued. Mothers killing their own children and then turning around to kill other children, people at the Eternal Party releasing the caged goblins, kids at the same party going berserk and immediately exploding upon attacking the crowd... the whole thing severely reduced the numbers of my fortress.
Then the goblins came back. They killed everyone except Iden, the clerk and last of my starting seven, as well as her baby, and a couple of prisoners who nobody let out even though their sentence was over. Iden ran around on the surface with her child for days, perhaps weeks without getting tired, before eventually running into the fortress and getting cornered in the stone/ore stockpile. She and her child were captured and executed. This left only the two prisoners, who slowly starved to death while the goblins went to the former zoo to party.
The moral of this story? There should be an easier way to spar without injury.
I mean, I was using metal weapons for all of the sparring after Mebzuth's, so that part was my fault, but Edėm and Mebzuth were training with their bare hands and wooden shields. I mean, come on.