I think it's less about cap hits and more about the systems that superstar led teams are forced to play. A coach builds a game plan around 1 or 2 players and, for better or for worse, forces the rest of a lineup to fall in line. You end up struggling to roll four lines and thus struggling to develop a team identity. It's not a way to win a championship in the NHL, on average anyway.
You win by committee and in today's NHL it seems obvious that a team needs to attack in waves. It's why LV, LA, DAL, VAN, NYR are the odds on favourites. Good teams where no one is held up on a pedestal and buy in by secondary players is easy. And it's why TB had a dynasty, STL won a cup, LA in their prime, BOS, CHI previously etc... Counterintuitive yes, but superstars are a SMALL part of the equation. They never trump balance. EVER.
I don't trust COL to build a dynasty or TOR or EDM, I hope CHI doesn't put Bedard above all else. The common denominator is that in the NHL it's harder to build around a couple superstars than it is to build a complete team that is well coached and executes a horizontally stacked system.
If you're going to trade for McDavid fine (never happening but for
@bert arguments sake), but not before you have a fail safe way to get him playing cohesively with the rest of the team. Nothing against McD but you need to close the gap between best player and worst by way of a system that works for everyone and that isn't a given..