Lycaeon: i wrote a short summary, but i'm a under a bit of medication and my brain is a bit fuzzy. So please excuse me if something is not clear enough.
So first thing to note, i have experience using the military, both ranged and melee.
I made a basic underground design for a small stable, and I was trying to find the most pleasing aesthetics for it. In the mean time I was experimenting with aboveground defenses for fun. So I played the same embark four times redesigning the underground and changing things around above and watching how it unfolded. Saving them wasn't the point.
I armed my civilians with combat rifles in every stable i could, and they used bronze ammo. They didn't got any armor and they didn't train. I tried to get as much wealth from salvage as I could(~1.000.000). I also prevented the wild life from coming to my site, as i trapped a large radscorpion behind a stone door. Archery targets are like honey to them; [BUILDING_DESTROYER] is easy to exploit. I had to do this because bloodwings are bear sized flying badgers, only there is more of them. With a small militia you have no chance against them, and I think wild life should be more manageable at the stage of the stable when you actually care about it. Later there are more interesting enemies, and legendary axeponies butcher anything anyway. Burrowing underground against everything is just boring, even if it's more realistic to run than to fight. So I think there should be a lot fewer of them at every one time.
My stables died mainly to raiders. First stable's militia was using simple melee weapons and bronze security barding. Fortifications were a simple wall with a bottleneck. Six ponies aren't enough against three ambushes, and sledgehammer and four shields are deadly combination for a crazy unicorn. Blocking every bullet is nonsense. Civilians were useless.
On second try I used a dodge me trap with with four turrets. They couldn't shoot fast enough, a lucky raider got in, killed everyone.
The third died to a minotaur reaver. Simple wall with a door on it. It got through, killed everyone. It wasn't the one with the hood, but the one after it.
The raiders took their time, and didn't come to that stable.
Number Four died to raiders again. My militia were the same ponies as in the first stable, and they did better this time. Still, six melee ponies aren't enough to hold a stable against raiders. One got wounded, then another, and another, and one by one they ended up in the hospital. Then the raiders just walked in and killed the civilians, then the resting soldiers.
I don't know, guns don't seem to really work with low skill. Every bullet gets blocked by shield wall. Then the hostiles get in close and end it in a few hits. I'm aware that I should use guns from behind fortifications, (i almost always have sniper towers around the map) and wait for lucky hits, but most of the time i run out of ammo sooner then my enemies die. Then i just sit on my thumbs again, and wait for them to leave. Again, burrowing down is boring. I think the game is most enjoyable when you are not sure about the outcome of a situation, and you can decide both ways.
Also, ponies kick hard. I have read more than a few combatlogs, in which the enemy (not the ones with shields) died in less then three kicks. Now i always give my future military commander 3 kicking, 3 dodging and 3 teaching at embark. They are quite good against feral dogs and smaller wild life even without a shield or weapon.
Maklak: i played around in ten or so worlds since i found this mod, there wasn't a single time i could order saltpetre or found an embark that had it. Grinding rocks for it is not an option. Mining too much decreases fps like crazy, so i have to limit how much i dig around. An obsidian farm is too much hassle in the first few years, and eats up fps too.
Indigo: Yeehaa, another farmer.