I could have sworn that there was a rule that allowed you to use a weapon if your Strength was less than than the minimum Strength for the weapon (e.g. -1 for the Short Sword or +2 for the Long Bow), but at a penalty (what the penalty was, I can't remember).
However, I can't find that rule in either 5th or 4th edition. Was this maybe a house rule, am I thinking of some other game system, or is the rule buried incredibly well and I can't find it?
Well, I consulted LoM, but couldn't find anything, Maybe it's from Grogs?
Wouldn't have been in Lords of Men, since I haven't seen it yet, and I did a search in Grogs for Strength and Minimum, with no luck.
Nothing that I can see.
There's no mention of even the strength requirement outside the weapon table in the core book, and the table very strongly indicates this is a simple binary requirement.
I can't recall if the Core has rulings or not either. It would depend on how much realism you want in the story? As a (lazy) gm I'd pick a single number and have that apply, like -6 to all actions while attempting, or the weapon cannot be used at all.
Or if the point is that the character's strength is close but not enough, then use the deficit as a base number and apply a penalty three times that base. e.g. When a Str +2 weapon is wielded by a Str +1 character, they suffer -3. Then -6, -9, etc.
The strength rating is supposed to represent what base strength you need to wield the weapon effectively in the way it was designed to be wielded. I can easily see you using a one handed weapon 2 handed(while still using the one handed weapon stats) and getting a +2 to your base strength (also affecting damage output) if you do so. This is not in the rules, but seems an easy fix to the perceived problem.