That's not true. Luke failed. Vader's conscience is what won, in the end, and there's no real evidence that Yoda's training of Luke impacted the result. No way of knowing if being faced with the proposition of being cuckolded into watching his son's murder wouldn't have broken his resolve, whether or not Luke had been trained by a jedi.
Fair point.
Not sure where that leaves us in the world of comparing Levy with Yoda, or not being yoda.