Compared to the previous games, ARMA 3 seems to be more deadly. I attached a <i>handleDamage</i> to a unit to try to see why. I discovered that there is something weird with the way damage is distributed to individual hitpoint components.
It appears to me the engine uses a weighting system to determine which hitpoints were affected by a received hit - the closer a hitpoint is to the hit, the more damage it receives. While I do not believe this can realistically represent injury that is not the point of this ticket.
The problem I discovered is that either the weight calculation or the hitpoint definition on the models is incorrect. This is very clear for hits that land in the <i>general</i> vicinity of the head. It seems that anything above the abdomen results in more damage being dealt to the head (<i>"head_hit"</i>) than to the torso (<i>"body"</i>). From the chest area upwards, the head damage actually becomes equal to that of a direct headshot, making even a pistol shot a one-hit kill.
Since a picture is worth a thousand words I created a short video which describes the problem (make sure you have annotations enabled): http://www.youtube.com/watch?v=x_S4jjJ7dCE
A more detailed tabulation of values for individual hits can be found in the attached picture (<i>damage_distribution.png</i>). {F19287} {F19288} {F19289}