Hogwash. When you are attacked, you don't stop and assume the classic Rodin pose and decide what an appropriate reponse is, you incapitate the attacker and eliminate the threat. The attacker decides if it is worth dying over.
I think my view encompasses yours but I'm addressing the broader question about defence in general, not only the specific situation of defence against a one on one lethal attack. Society agrees that defence against such a lethal attack may itself be lethal. Society would see it as disproportionate to kill someone coming at you with a banana. Society does have rules about self defence.