But tell me, how long does it take for a warrior to learn to fight with his left hand as good as his right? Additionally, is there a reason a warrior should gain some advantage to using his off hand over his dominant?
Many skills reach a point were further training is moot/impossible.
I'm just playing devils advocate.
Many people never get as good with the off hand as the primary, if it was casually possible to do so, then every player in baseball would be a switch hitter. . . heck, if it was even HARD to train up to equal or near equal ability there would be loads of switch hitters. The real world evidence would seem to indicate that it just may not be possible for most people to ever overcome their primary side bias completely.
But are not PC's special? Or at least different from the average Joe?
I would say that being a player in the premier league of a major world sport is competitive enough to say that the comparison to PCs is at least fair. . . .and NPCs can use TWC too.
My favorite rule after the "Golden Rule" of:
"The GM can change any rule they want for their game."
Is the "Sauce for the Goose" rule of:
"Anything the PCs can do, an NPC can do to them."