I actually think Hedman is better than Kronwall personally. If I had to list them, it would go something like this:
Karlsson
OEL/Hedman
Kronwall
Hjalmarsson
Brodin
Edler
Ericsson
Maybe I'm just a big fan of Kronwall, but I'd take him over any of those guys (for a one-off game, not to build around...that would be Hedman or Karlsson or OEL because of how young they are). If we are talking about value to a franchise, I'd probably use the same order as you have there. But if we are just talking about better players, I think Kronwall is more complete than all these guys.