Rebuilding or not, it's just a bad, bad, bad idea. You don't need to preface it.
There are some people that are absolutely in love with players potential and way oversell the value of the 4th and 5th picks.
Over the past decade there have been some very good player around that slotting, there have been some ok ones. There are more of the "I'd rather have Tyutin" than that pick. There are only 4 or 5 players during that time that I'd rather have than both Tyutin and Johasen and that is if Johansen doesn't improve from where he's at. If Johnasen starts putting up a 60 point pace that number might even decrease more.
I can be persuaded that its not a good deal because we'd be losing purely in terms of the trade value of the players, so that much needs to be added from the other side.
Allow me to explain why I think its a good deal in outline. You'd be right that historically speaking a 5th overall is lucky to turn into
either Johansen or Tyutin. But this is Barkov/Lindholm we're talking about. I think its smarter to make projections based on who they are as players instead of their draft position.
I'll admit that much of my reasoning here comes from the idea that the value of a top prospect is bound up in the possibility that they might be great. Quick thought experiment (not about specific players): would you trade a second-line level player for a player with a one-third chance of being second-line, one-third chance of being first line or elite, and one-third chance of being worse than second-line?
For me this is an easy yes, IF you have higher depth in your lineup and a lack of elite players. The value of a player should rise exponentially, not linearly, as you progress from second line to first to elite.
I don't think this is a "rebuilding" trade either. Johansen is still not that useful and I don't think he has much top-line upside, and Barkov/Lindholm could easily outscore him next year, which the Desjardin's equivalencies suggest:
Jonathan Drouin, Halifax (QMJHL) 19-30-49
Sasha Barkov, Tappere Tampere (SM-Liiga) 18-22-40
Elias Lindholm, Brynas (SEL) 15-25-40
Nathan MacKinnon, Halifax (QMJHL) 17-22-39
Max Domi, London (OHL) 15-18-33
Hunter Shinkaruk, Medicine Hat (WHL) 14-19-33
Sean Monahan, Ottawa (OHL) 13-20-33
Anthony Mantha, Val d’or (QMJHL) 17-13-30
Valeri Nichushkin, Chelyabinsk Traktor (KHL) 20-10-30
Adam Erne, Quebec (QMJHL) 9-15-24
Curtis Lazar, Edmonton (WHL) 13-8-21
Tyutin is a very useful defenceman though, I'll give you that. This is the sort of deal that you only do if you think the younger defencemen can step up.