Your point about staying on departure time is exactly dead on. That is why most people have jet lag flying internationally whereas I have little if any, usually flying economy class and not taking any drugs or medication.
this is the reason i liked the non stop PVG-DTW when they had it because the departure is in the morning so corresponds to sleeping. the PVG-ORD flights on UA and AA are in the afternoon which forces me to stay awake the entire flight, which is part of the reason why i don't plan to ever redeem premium rewards for that route on those two airlines (their asian partners is a different matter
)