A 16" is not practical for dueling, unless you keep it in your off hand. Like (I think) epee fighting. You have a long blade for your main, and a dagger in your off hand. The dagger can assist in blocking, and does exceptionally well for in-close work. You actually put a thought in my head last night. There's an old saying, "A samurai always carries 3 swords." A katana (36"), a wakazashi (about 24"), and a tanto (about 12"). This set up would make a pretty wicked cos-play. Samurai-Jedi
To the best of my knowledge, epee simply means "sword", and is a form of modern sport fencing. The guard and blade cross section differs from a foil, as do the target areas, but both are thrust-centric weapons.
A dagger would be used fairly often with a rapier, and often in films the rapier is represented as a cup-hilted epee, so i suspect that's where it comes from

In certain schools of rapier fencing, the dagger was known as a parrying dagger, in others it was called the 'main gauche', but that just means 'left hand'.
I agree on the useage though, 16" is alright for a spear, but that's about it. As a lightsaber's blade cuts as easily as it touches, there's not actually anything to gain from using a short blade on a spear though, so it's probably limited to aesthetic purposes and tonfa use for the most part.