comparing this games combat system to for honours or assassins creeds makes me think that in terms of complexity and realism it easily beats both, but is less rewarding. the reason being, that there is no distinction made between the animations of a lethal and a non-lethal hit in KcD, yet in AC and FH every kill plays out as a small "fatality". The insane quality and variety of ACs killing-blows can even convincingly divert attention from its combats shallowness.
The State of the Game:
In a fight, if a weapon makes contact with a character, it reduces his stamina. if he still has stamina left after the hit, a fitting "flinch" animation is played, else he simply becomes a dead ragdoll. this use of ragdoll-mechanics can make for some quite comical kills..if an armored body-section has been hit, sparks will show and the damage is lessened, but can still kill. the trajectory of the attacking players sword does not seem to be influenced by all this; it more or less glides off the opponents clothing or armor.
Im assuming that as soon as the blade makes contact, an if-clause determines how the character receiving the hit should react. If lethal, instead of activating the ragdoll immediately, why not continue the striking animation in a more dramatic way, by adding some impact? once that animation is done, ragdolls can be used to further move the corpse.
For Example: A potentially lethal, diagonal hit from the top right, hitting somewhere between the neck and the upper-arm (Zornhau) takes place
-the hit is non-lethal: let the sword glide off and keep the flinching animation. by flinching, the opponent gives in to the strike, preventing it from cutting through him.
-the hit is lethal, the section unarmored: the opponent does not get to lessen the blow by flinching. because he does not get partially out of the swords path, it clearly cuts into his body and gets stuck somewhere near the shoulder. whatever action was being carried out by the hit character is interrupted; the impact makes him hunch over a little. next his body loses tension. he drops to his knees (optional) and lets go of his weapons, blood is dripping from the wound, his eyes and face become pale. finally a kick to the chest lets the attacker loose the sword from his opponents body, making him fall over backwards.
-the hit is lethal, the section armored: if the weapon can punch through armor, like a mace, the same killing animation takes place. instead of a bleeding wound, the armor receives a dent and its wearer some bone fractures. if a cutting weapon is used, the hit does not kill. instead its impact forces your tired opponent to the ground, where he is helpless for a while and can be finished off, unless guarded by companions.
Another Example: A Thrust to the stomach
-non lethal: a few steps backwards (flinch) help your opponent mitigate the damage.
-lethal, unarmored: after making contact with the opponents body, you take an additional step forward, driving the blade further in. he definitely collapses to his knees from this and hunches over, covering the wound with his hands. He then falls to the ground in a forward or sideways manner, once you pull the sword back out. (without a kick this time, since its not needed - im not asking anyone to apply unnecessary or unrealistic badassery to this game, just to be perfectly clear ^^).
-lethal, but armored: the armor prevents you from driving the blade further in, so your step forward pushes the opponent backwards, causing him to struggle for balance. (maybe, if there is an object behind the opponent blocking his path, he could stumble and fall over backwards.. maybe, im asking for too much)
the beauty of what im suggesting is that the striking animations dont need to be changed for it, because the outcome of each strike is determined by the opponents reaction. if the Zornhau is lethal, then only because the opponent failed to block, dodge or give in to the strike (flinch). the only difference between a lethal and non-lethal striking animation is, that the lethal one is stopped shortly after entering someones body, and then continued in some kickass way ^^.
Also just imagine what it would feel like to be finished off by an npc in this manner.. for a games world to be immersive, its characters need to command some respect from the player. having grim and personal death animations, that have you look into the eyes of the person you are about to kill or be killed by should add to this, im sure.
for inspiration on fitting kill-animations, you could take a look at Total War: Shogun 2
and finally, feel free to add your ideas or criticism in case im wrong or my grammar annoys you ^^