English

This is not the first time I have witnessed this thing happening.

The Matsian Border guards periodically start fighting each other, killing eachother in the process. Seriously, If you sit there for any time, about half of them will have killed each other.

What's up with that?

Um.. I hate to say this, but the Matisian Border Guards aren't recruited from the top of the barrel, if you catch my meaning. Their skill with the ranged weapons they use also is not so high that they can hit the broad side of a shalah with a rifle, so they use launchers on the grounds that "close enough" is "good enough".

That means, of course, that when the sword bearers go out to engage an enemy they often catch some of the edges of the explosions. Instead of saying "hey, you owe me a beer for that!" then they decide to take it out on their fellow tribe members. It's one of the consequences of their isolation.

The npc AI isn't the brightest. You can see the same with bandits sometimes, you hit one and then the rest might start fighting each other.

I think the NPC AI was based on Celebrity Deathmatch.

"You know the rules? There are none! ... Let's get it on!!"