Bay 12 Games Forum

I've been experimenting with a creature/civ.. I made it have quite high stats and immortality. In arena tests, they're regularly able to take on 2 or 3 Humans with equivalent skills/equipment, and are a match - unarmored, unarmed, unskilled - for elephants. They have equipment usage mostly copied from Humans, and job performance copied from Dwarves. I expected this to give them steel equipment, and allow them to use it. They also have a 20-year breeding period, which I figured would nerf them...
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I made several worlds with them, and noticed something. In just about every single world, they're gradually steamrolled by other civs, megabeasts, wolves... Or anything at all, really. One town had over 60 people killed, along with lots of their tame bears, tigers, etc.. by a single dragon, who was then killed by a camel. Earlier in that town, a single minotaur killed 10 people in one rampage.. Without dying. In the Arena, a single swordsman with Iron equipment and Adequate skills was able to kill a minotaur.. And the only wound was a cut open hand. It's worth noting that the hand cut open was his sword hand, and he dropped the sword. With that being the first strike. So, with no wrestling or striking skill, he was able to avoid damage long enough to punch the minotaur's head into gore after 8 pages. To test that this wasn't a simple fluke, I spawned in a new, unharmed swordsman.. And he was able to kill 3 in a row, losing his sword on the second one, before dying. I then did a 5v5. Swordsmen won. 2 were unharmed, 2 had a single limb ruined, 1 was mortally wounded and died about 30 seconds after the fight.
Confused at why such excellent warriors always fared so poorly in the Real World(tm), I spawned an adventurer in one of their few remaining hamlets. Even though I tried to spawn as locally important, I was still a peasant and had to travel some to the mead hall. When there, I saw.. 0 warriors.

So, I've got two questions.
First, how can I make them have soldiers, like they should, so that they won't always be steamrolled?
Second, what are the general factors in making something balanced in worldgen history? I tried to make these balanced with a long breeding delay, and have yet to see if that succeeds, but it'd be nice to hear what people have found.

On my most recent fortress, I embarked as part of a dying Dwarven civilization. It had one remaining hillock, and everything else was conquered by some neighboring Elves. I started sending my squad of 3 swordsdwarves on raids to neighboring Elven Hillocks.. And then they came back wrong from one of them. On return from a pillage, one was promoted to a Baroness of the hillock I raided. Another naturally became the Baron consort.. And the third became the General of my civilization. What are the implications of having a baron of a hillock - belonging to an enemy civilization - in mine? Is it just another noble to make rooms for?