There is a bit of a conflict about sword lengths in this chapter. First is says that when fighting a duel you should use matched swords, as to not give the other person an advantage in length. Almost immediately after is it talks about how weapons should be matched in length to their users, a large man using a long sword and a smaller man using a smaller sword.
Next he stresses the importance of knowing a wide variety of blows and reiterates that cleverness trumps strength.
A ways down he again says that a longer sword is more dangerous than a shorter one.
Vadi has a great love of the longsword, choosing it over all others whenever he is in a fight. This is rare, as most masters we study teach a variety of weapons.
Finally, prefer lightweight weapons that you can easily control.