I'd say Drouin, based mostly on having a higher ceiling, and evidently more talent (which tend to come hand in hand anyway).
This is because both are sort of unproven. They've both shown glimpses of being solid top 6 forwards (even first liners) but haven't maintained it (partly due to injuries, and other circumstantial stuff like coaching).
Drouin has more offensive upside and was a much higher pick.
I won't necessarily disagree about the upside favoring Drouin, but draft position should have no bearing on it one way or another.
If we're talking about the trade value for players who are still young and largely unproven, I think draft pedigree still has a significant impact.