This is ridiculous. Both players would have had very good rookie seasons if they put up 50-55 points in their post-draft year. 90 points from McDavid as a rookie?
No one who's seen a lot of McDavid and follows the NHL thinks the kid is going to put up those kinds of numbers in his rookie season. It's not fair at all to this kid to put those kinds of expectations on him.
Putting talent level and projections aside, Eichel is probably more prepared to jump right into the NHL grind. He's bigger and stronger, plays a more NHL-style game whereas McDavid still needs to fill out and will have more adjustments to make when he can't dance around guys as easily at the next level. It shouldn't surprise anyone if Eichel has a better rookie year even if McDavid is a bit better of a prospect.
Anyone who thinks McDavid is just miles better than Eichel is most likely not in a position to fairly judge both players, because those who've seen a good amount of both do not feel that way, including NHL scouts. Is McDavid better? Yes. Should he be picked 1st? Yes. It's still close, though, and it wouldn't be surprising if Eichel is ultimately the more effective NHL player.
Hanifin should be talked up in this group as well. McDavid is a better prospect and should be picked ahead of him, but he's right there with those two. There is a tier of three players at the top of this draft in my opinion, at this point in time anyhow. After McDavid, Eichel, and Hanifin you get the next tier of guys like Kylington, Konecny, Barzal, White, Andersson, etc... too early to split the rest of the top 10 or so into a 2nd and 3rd tier.