My understanding is that Euroleague defensive rotations are pretty sophisticated. I don't know about "culture", but the demands placed on European players defensively are no less (and probably greater) than NCAA players. It's obviously still projection from there to the NBA, but that's true of all prospects, whether from France or from Duke.
More importantly however is that I am not a believer in the narrative that defense is mostly a question of effort. Maybe that was the case in the 80s, and it's certainly the case in local pickup games at the Y, but with the amount of switching that goes on in the NBA today, I don't think it's accurate at the NBA level. There are just skills involved that I'm not sure we can hand waive away. My read of the reports on Yabusle is that he's just pretty clueless on that end.