"exhausted only because he allowed the fight to be prolonged"
This is a confusing stance to me tbh. Even if Yoda was holding back against Dooku in the fight his energy expenditure shouldn't be that much then what it would take to combat Dooku's own. While I'm not arguing that Dooku is on Yoda's level or even extremely close he's certainly not in oneshot territory or vulnerable to being stasised if prepared. That's shown pretty clearly in the fact that Yoda didn't do exactly that at the start of their fight.