I'll be rooting for Sagan, but just don't think he can hang with the likes of van Aert and van der Poel. If wet, obviously bike handling skills will be more prominent. I'd think van der Poel would be the favorite then. Maybe, just maybe Sagan in adverse conditions if he stays upright.
Having said that, it'll probably be someone like Stybar, Asgreen or Lampaert.