When a person get a hit to his helmet he hears a clang quite louder than when he got hit in any other part. Small but nice addition that will increase immersion.
Plus a temporary blurry vision might be nice also for strong hits or a small fade out and then fade in of the surrounding sounds. Something like a temporary (1-2 sec) loss of clear sight and hearing.
Certainly one more reason to aim for the head.
I am very much for this, having been hit in the head while wearing an accurate sugar loaf helm I can tell you that it is definitely a minimum of 1 second of being jarred to the point where you lose your target. Especially on a full power blow from a mass weapon, like a mace or a hammer. I like the idea of blurred vision or something similar to shell shock like you see in FPshooters.
it was discussed in other threat and majority decided that visual effects are annoying …
But still if it could be less than 1 sec and depend on how heavy weapon is
like sword - 0.3
falchion - 0.5
mace - 0.6 (or much less because mace is “berserk” style and it will be somekinda cheat if you spam hitting someone)
2h sword - 0.7
halbert - 0.8
then it should work i guess