How much would Strength actually contribute to weapon damage (read the OP)

[Knaight]

All I could think of when I read this was, "isn't that basically what base attack bonus and feats model?" Skill with your particular form of combat is, in Dnd terminology, just character level to some degree or another.

Pretty much, though there's some weirdness in what overlaps, and some weirdness in defenses.