Now this is a discussion! Classical swordsmanship teaches to cut down an opponent with one or two moves, usually a parry followed by a killing cut, or a wounding cut followed by a killing cut,or a one move killing blow as you stated.
Also, don't forget, the power of a deceptive strike followed by an immediate killing slash.
JYD #54
"Put your hands high, let your arms be the pillars that be holding up the sky..."
