Well Practice sword is for practice so
In game we can practice different type of two handed weapon
As you know in two handed swords they have certain features
Length
Yeah but you know, unlike in real life, in this game you can practice with sharp weapons and even kill your opponent without doing any harm because he will respawn anyway. That's why practising with Longsword is possible and is even better than with technically "practice" weapons, so you don't really need a new weapon mode for that.