Bad information here... that's not what swords weigh.
Its not only about the Weight . they are often quite similar (You're right with that) but they CAN differ by more than 1 or 1.5 Kilograms and that IS a Difference, especially if You want to do more than just Chop down at the Enemy.
Swords are not automised and the Weight of the same Category could differ by 1/2 a Kilo ( especially Long Sword or Bastardsword. a Claymore or Two Handed Sword maybe even by a Kilogram)
its about the Movement, the Momentum and changing it, which comes with Fiore Dei Liberi
It simply can not be done with a larger or heavier Sword than a Long Sword ( I wouldn't even do it with a Long Sword, but I was STR 3 (or 4 at best ) )
Swords are very very light & extremely well balanced so the weight is almost entirely in the hand.
Not so much with a Bastard Sword that can be carried with one Hand but you most often need both Hands to fight with it effectifely
In that a European Bastard Sword is even better to use 1 handed than a Katana because the center of Balance is closer to the handle.
not the One I used to fool around with ( I wouldn't call it fighting myself. Training, yes but not fighting)
The misconceptions about sword weights is remarkably widespread but at no point is 7/10ths of a pound going to "break your wrist even for a Str 6 Character."
according to my own Experience I've had with Sword, Long Sword and Bastardsword
a Bastard Sword is unsuitable for the one Handed Maneuvers you need for Fiore Dei Liberi (especially a Bastard Sword in one Hand and a Swordbreakerdagger in the other)
fighting with a Bastardsword with two Hands and using Manuvers presented in Kunst des Fechtens is OK though
With a Swords Dance
Medicineman