Hi, I guess I'll be the first to ask you to sign in with your full first and last name, as stated by the forum rules.
(I've always wanted to do that)
Full armor encounters in ARMA training are more akin to scientific experiments rather than re-enactments; we practice historical techniques and test how they would work in practice.
Example:
http://www.youtube.com/watch?v=ZnqOMbFDEAI
Swinging a sharp sword against plate armor is just a good way to destroy your sword and waste energy. Rather, one should halfsword, grapple, and wrestle to stab at gaps and weak points in the armor like in the video I posted.
As for group armored encounters, I don't think enough members have full sets of gear to pull this kind of thing off. Even if we did, however, with the lethal techniques that are historical, such encounters would be incredibly dangerous (if not illegal), even with blunt swords.
The mortschlag, a halfswording technique meant to bash helmets and skulls, can be just as lethal with a blunt sword as a sharp. We would not want to risk someone getting killed or injured in the chaos of a group battle.
Welcome to the forums!
"...But beware the Juggler, to whom the unseemliest losses are and who is found everywhere in the world, until all are put away." - Joachim Meyer