you�re only partially correct.
swords most definitely do NOT have the same swing speed. different swords were created to do different things. some were made to slice through armor, some to pierce, some to slash, with quite different weights.
the sword stroke(s) itself seldom killed. and actually, they weren�t meant to. your goal was to leave your enemy to bleed to death.
what you see in modern fencing is what developed from dueling. the re-introduction of the piercing sword. lightweight, fast, short(er).
these swords are very, very fast and move in what�s often referred to as �double-time� (2 moves per 2 beats, as in parry/riposte versus the �older� way - thrust, recover). however, i wouldn�t want to rely on one of these in a large fight with heavier swords � it wouldn�t last.
the term double-time also refers to the use of two fast swords, sword and dagger or sword and poniard. absolutely there have been times in history when two weapons were wielded at the same time. if you have a fast sword (capable of double-time) along with a poniard (for example), i can entangle, deflect or parry your cut/thrust while moving in with the poniard and impaling you. Double-time = my two moves to your one (as your heavier and/or longer weapon moves in single-time, meaning slowly).
you would probably not see two weapons being used simultaneously against a fast double-time attack now, as (for example) a single epee is already moving in double-time.
i certainly can�t speak for everyone and every style, but I�ve fenced (primarily sabre) for 34 years and taken a martial art for 23 (karatedo). And i can tell you that in neither art do we truly present a sideways target � though competition fencing is more sideways, depending upon the sword � but that is not real fighting.
it�s much more like kata in martial arts � a dance of movements designed to teach technique and form, not actual fighting.
in order to utilize both of the sabre�s cutting edges (the entire �front� of the blade and the �top back half� of the blade) i must be in a more squared position.
imagine, if you will, being right handed (thus sword on left hip), standing sideways, attempting to draw forth the blade AND cut in the same motion (an object directly in front of you). cannot be done with much force or accuracy, or without �opening' your right shoulder (while the blade sails wide) and destabilizing your balance.
now. imagine standing only slightly right leg forward but more or less straight up (facing). pull at the hilt and give a quick rotation of wrist � thus slicing with the back half edge of the sword (you�ll end up as though you�re holding a frying pan). see? speed, strength, deadly accuracy. and you�ve maintained a defensive posture and balance.
mostly (in �real� fighting), you would actually only move sideways in response to an attack by your enemy. by standing straight up, i allow myself to slice in eight directions.
hope this makes sense.
