If we drafted McDavid, I would be looking to trade RNH within a couple years, once McDavid has been established enough to hold a #1C spot (which shouldn't be long, if done correctly). You can't run three #1 C (RNH,McDavid,Draisaitl) on one team, regardless of what others say. People will bring up Colorado and such, but look how they've been doing. #1 C's require a sufficient ice time and quality teammates, and there's only 60 minutes of ice time in a game, it just wouldn't work.
RNH and McDavid share a similar skill set, with McDavid being obviously better. Draisaitl offers a more diverse skill set, making him a good choice for the #2C.
I would trade RNH for a top 2 D.