Realism; Strength is not important for swordsmanship(?)

[mhd]

People generally have a much lower threshold for acceptable wounds than PCs do. Bleeding to death or dying of gangrene can happen from pretty small wounds, and in real life you don't know about your HPs or whether you properly made a HT check. (Which is also why armor in the real world was a bit more "binary" than what fantasy adventurers wear)

So "sufficient" strength is probably quite low, especially if no armor is involved, although I'm quite wary of any differences that come in straight orders of magnitude.