study Di Grassi (Italian), you'll use your rapier and dagger differently from if you studied Thibault (Belgian school). Not hugely differently, but it will be different. Study the Spanish school (Destrezza), and you approach enemies differently, and even hold the blade differently. All three are valid and work well with identical weapons. Not all of how it is used is derived from the shape and size...
The trained reactions differ, too... conversion from one to another isn't trivial.
Few RPGs model different training schools' differences. they do make a difference.
