I'm not really sure what the base of the argument is. We don't need Monahan to be better than Barkov to be the 1st line centre on a championship team.
They are comparable player with similar skill sets. One is better than the other, one has a better supporting cast. Maybe Monahan doesn't need to focus on his defensive game as much with the emergence of Backlund. He doesn't see the same types of match ups that Barkov does. The difference is marginal enough that IMO, it wouldn't be worth giving up growing chemistry among a young group of players to trade them 1 for 1, even if Barkov is better.
I think for this generation of players under 25, it will be a similar situation to now. Where you have Crosby, someone who is obviously the most talented player, and then a whole host of elite players (Toews, Bergeron, Kopitar, Kane, Doughty, etc...) that maybe don't get the reverence of the golden child, but are more than capable of leading their teams to championships.
So now you'll have McDavid and then a whole bunch of Monahan, Barkov, Gaudreau, Eichel, Forsberg, etc...
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