First of all, I don't know anybody who needs to hit someone 10 times to kill, unless they aren't a melee class.
In that context, people usually die in 3-4 hits, and that is why I believe that disabling the player altogether is much more important than just taking off the damage from him, where he still poses threat to your team.
You're nit picking to suggest I even think 10 hits would be required it was simply an example. Like teeth has said, you never have an indication on how wounded someone is so why should you be rewarded for luck? Anyone trying to hit another player is trying to kill them, actually causing them to die is fortunate nothing more.
I do however think there is a problem with ranged calculation though