"...the first priority for anyone who knows anything about fighting [again with the insult implying he is smart and you aren't] is to disarm your attacker if you have no weapon yourself."
The guy doesn't know what he's talking about. Covering the attack and gaining control of the knife arm is the first priority in unarmed defense. Fiore's manual makes this abundantly clear, and I believe him to be correct. All his plays start from covers and come about from having gained control of the arm.
"Furthermore disarming is one of the easiest things you can do once you know how. The body mechanics of the wrist and hands can be easily manipulated with the right applications of force, which make it impossible for even a very stong person to continue holding their weapon."
I would not say disarms are easy, but they are possible. However, they will not work unless you have control of the attacker's arm. It must gripped well and generally isolated, such as in the armpit armlock, which works really really well even against an experienced man.
Ah yes, it is SOOOO easy to disarm an armed man... This sounds like the stuff the Jujitsu practicioner (1st Dan) said right before we sparred. I massacred hum in sparring when doing hand vs the knife (I have zero formal grappling training).
This is not surprising. Unarmed knife defense against a cautious and skilled knifer is just about the hardest thing to do in martial arts. I've played with this stuff for a long time and I often get "killed" by experienced cautious players. If the guy thought he could win, then he has not spent enough time training and freeplaying.
That said, I must remind the readers of this forum that your typical knife attacker is not an experienced knifer, he is a punk who has little to no training. SEcond, his attack will not be cautious but committed, meaning he will put everything into his blow and it will not be preceded by a feint. All knife defenses are designed to address this committed attack. You, the readers (not necessarily you Tim) , need to understand this fundamental truth when you are training. If you do not, you will not understand why you do certain stuff and why it works in the real world.
Virtually impossible unless you really, really work it. You will have better luck grabbing and controlling the arm then working the hand or wrist.
Yes! Absolutely. That is the key.