You are completely missing my point (lol) The point system in the game can be used in various ways.
It can be used for scoring, but it is mainly used for deciding how to proceed in a mission, well usually anyway.
The higher the points (meaning you killed many people or completed tasks) could change the way the mission is played out.
Negative points usually occur when the mission is failed.
I, in no way associate this game with Splinter Cell, in any form at all. This is a Military sim, and there are some things you cannot do in this game without using features that almost seem arcade-ish. But it is not used for that at all.
Say you rifle butt someone, it adds to a variable to say you knocked him out, and a few others too. This variable alongside the point system can easily create another path for the player to take.
In ArmA 2's campaign, there were main missions and side missions. If you do the side missions the outcome of the main mission will be different. But the side missions also have many different ways of completing it, either by failing it, or for example you killed the commander, but not enough of the enemy troops, or you killed the troops but not the commander etc. Then depending on how many people you kill (for your overall score) aside from killing the commanders troops for example can have 2 different outcomes.
Anyways enough of that, back on topic.
If you knock someone out, you can still hit em and kill em lol. War is brutal, although I would expect the NATO side to capture, but maybe the enemy side not to.