Eh, sorry Pantom, but Master Sigmund fenced in actual battle. As in for dear life.
Additionally Historical fencing is a martial art, and has nothing to do with the modern sport of fencing.
His advice is sound. Rely too much on defense and you will be defeated.
He does not say that defense is NEVER a good option. Certainly not. But to rely exclusively on it makes you a bad fencer 
I don’t know how far back you’re going with Master Sigmund, since it’s true that in Medieval times it was far more about finding the little places where armor didn’t protect you and going for those weak spots. This made the techniques entirely different from today, where the assumption is that you’re wide open everywhere. It’s not that it has nothing to do with today, it’s that the modern art of fencing evolved after the introduction of guns, which made personal armor superfluous and even counterproductive in battle.
And of course it’s true that things progress a little differently if you’re fighting for your life.
However, where you’re misunderstanding me is that you’re only faking going on the defensive. The idea is to make the opponent come for you, knowing where you’re going to dodge and then riposte. It goes back to whoever earlier said that the key is having the initiative, that is, having a plan that is just a little better than your opponent’s. If you do, you’ll win. If not, well, there’s always Valhalla.
When fighting armored, yes. But that was not always the case. Most masters spoke of BOTH armored and unarmoed combat with the sword (and other weapons as well of course).
Again, the modern sport is far removed from historical fencing because the modern sport is that: a sport. Historical fencing is a martial art.
It is BECAUSE of THIS that the arts are completely different.
Well then that’s an entire different concept isn’t it? If you hold the intiative then you hold the advantage. But in fencing and relying exclusively on that technique is likely to cause you problems, as it may be that your opponent is wise to your ruse
I believe that there are reasons why people learn offense and defense.
Doubt that anyone here has decided that either is dispensable.
And , again, most everything depends on the context. I doubt that there are many useful startegies that can be applied equally well regardless of the context. The ones that can be will be proportionally vague. The more useful the strategy w/o regard to the conflict, the less specifics it will have.