Safe to say that the top 5 are the names mentioned above. Kotkaniemi isn't a top 5 fantasy draft option for most leagues. Maybe if you have FOW I can see a reason for Kotkaniemi up there because Montreal will die on the hill making him a center after taking him 3rd overall (although most probably thought that about Galchenyuk too) but thats the only reason you can consider him up there.

4th overall is definitely between Tkachuk or Wahlstrom for most fantasy leagues that I know of. I dont think you can go wrong with either kid. I dont worry about the Ottawa situation for Tkachuk. A lot will change there by the time he's reaching his potential.