The longsword has 23 pierce trust; the great sword has 26 pierce thrust. I chose 22 because that's the smallest thrust for all the high end swords except the current katana stats. Actually, out of all the thrustable swords, only the katana and bastard sword have less than 22 pierce thrust.
And to be honest, I could care less about realism in contrast with balance, but if you want to make that a point of argument, nearly every other sword would be as valid as the katana at stabbing. A double edge sword might be able to split open a wound two ways, but the katana could just as easily expand in one direction. I don't know much about these high end swords, but it seems unlikely that most of their real life counterparts were actually made for thrusting any more than the katana was.