Driik fortification works against them.

[Saiko Kila]

Driik fortification works against them.

I rarely meet Njerp attacking other villages than Driik, which may be intentional, because they are supposed to be rich jerks. Maybe that's why some Driik villages are fortified, or doubled. But the fortifications are what makes them actually more susceptible, to death as I experienced many times. A note: I enter the villages mostly from west, so end on the wall opposite the entrance. This allows me to either step down on the outside, or inside. Often there are people generated outside the western wall, and Njerps too, and when I step outside I can see citizens fighting with Njerps, or when inside I can see citizens trying to fight - but unable, thanks to firtifications.

First example:
I stepped inside, and after a few turns I noticed aggravated citizens running in my direction with weapons. I thought that they want to kill me for some reasons, but they were coming to the wall and wandering along it. As it turned out, the single citizen outside was in that time slaughtered by a Njerp, because stupid Driik never thought about watchtowers. I rushed outside, but it was clearly too late, with the big distance to cover. I caught the Njerp, who stole weapons of the hunter he killed in the meantime, and ended him.

Second example:
I waited a few turns (learning from previous instances), and heard fight, so stepped outside. There was a Njerp trying to slaughter a kid in the southern section of the wall. When I ran alongside, I noticed a body of other kid in the grass, apparently disposed of earlier. Since I wanted to be a big hero, but was too far to be in melee range before it's too late, I shot a few arrows, which managed to inconvenience the Njerp. He tripped, lost his sword, and the kid started to kick him in the head. Which ultimately proved fatal for the Njerp. Now when I enter the village every time the killer kid (which recovered) is present outside the wall, just like the first time, and lingers near belongings of the first, killed kid.

Now these example show typical encounters of Njerps and fortified village: Njerp attack someone (sometimes more than one person), this one fights, but ultimately falls. The rest of the village "tries" to help by banging their head against the wall. I don't know, but if I made a defensive structure, I would want to help me in defence, and not hinder it. In all of these cases there would be no dead victims, because the Zerg rush of villagers (who are plentiful in fortified villages) would quickly overwhelm the Njerp.

What would be the way to improve this, I wonder?

[MeerkatRabbit]

I saw this same thing happen earlier. I was trying to stalk some Njerp guy outside the walls of a Driik village. At one point he surprised me and charged at me out of some trees but I ran away. I was too cowardly to engage him because of the whole perma-death nature of this game and I don't have much experience with fighting. I just wanted to follow him to see what happened if he made it to the village.

After running away and then trying to relocate where he went, I heard the sounds of fighting going on off in the distance. The Njerp had found a lone Driik housewife wandering around outside the walls on the opposite side of where the entrance was. The rest of the villagers were all enraged and swarming around inside the wall, trying to get out there to fight, but the wall blocked them from going out there and helping her.

Turns out that was the world's toughest housewife though. When I finally circled around the walls and got to the scene of the fight, I found her standing over the Njerp's corpse. She must have had a dozen stab wounds but she slaughtered that guy. I guess I shouldn't have run away after all. 

Maybe it could be fixed by just adding a couple more entrances around the walls of each town and widening them so the AI villagers could more easily get through.

[Saiko Kila]

If I were designing the game, I would add some kind of pass (gate), normally closed, which would be unlocked when the fights goes on. Or give shooting towers, with access only from inside, but giving ability to shoot over (like pine trees, some kind of fortifications). But this would only allow shooters to help, most villagers can't shoot, and shouldn't shoot.

Alternatively just teleport guys on the wall in case of emergency, as if jumped, and allow them walk off on the outer side.

When player enters the fortified village from the west, he is placed on the wall, and can choose to move inside or outside, I imagine it as a very high jump from running.

Survivors of attacks on driik villages often wander outside for the remainder of the game, I have encountered them years after the attack. If they are numerous and armoured, they will repel the next attack, but if not (like in case of the kid, or the housewife), then they most likely will die.