Don Durito
Hero
Remember the purpose though. If you're removing Strength and Dex from accuracy and damage then pre-reqs need to bear the weight of reinforcing class concepts. If you have Strength but not so much Dex you use a hammer or an axe. If you have Dex but not so much Strength you use a rapier or a shortsword.14 is so high above the average curve, though. I'd use 12 or 13 at Max for those kind of requirements.
Requirements could be used to keep things within thematics. I'd argue for 13 and 15 to be used, like with heavy armor's Str requirements.
Off the top of my head, maybe No requirement for light weapons, Str 11 for one-handed, Str 13 to use versatile in one hand, and Str 15 to use heavy? Maybe use 4Es Dex/con weapon groups for more spice.
Putting 14 Str 14 Dex for a Longsword is a way of saying "This fighter is a good all rounder, not especially huge and muscled and not as graceful as an acrobat - just incredibly skilled."
I think using a system like this you wouldn't need to worry about the whole light/medium/heavy distinction. What I'm brainstorming is a pretty radical reimagining.