Why are heads so tanky.
The human head is the weakest parts of the body, any significant damage to it is incredibly likely to kill or put you comatose, but in Kenshi, it has the same exact HP (Or more as certain races!) as the chest, or an arm. Furthermore, because of how the body part targetting works, you are always at risk in the chest and sometimes stomach, but almost never will you be downed from the occasional headshot.
If the head simply had way less health I think it would be modeled much better, because IRL if you dont protect your head in a fight, you're gonna die. It would make having a good helmet much more important rather than as just burst damage protection.
This isnt actually a hard fix at all, I'll probably end up making a mod with the FCS to bring most heads down to ~1/4 health, but I just thought it was a bit weird.
Edit: I made this into a mod, its here if you wanna check it out https://steamcommunity.com/sharedfiles/filedetails/?id=3721142007