The Swedes. Hughes just has way too much uncertainty around him, until a kid has proven himself above AAA hockey, I tend to ignore the hype when it comes to NHL potential. Due to that, I'll take the Swedes. Remember how guys like Wise was viewed just a year ago.
I think Matthews will be the most impactful player, as elite-centers tend to drive play more than any other position on the ice, and the gap between a top line elite center and a 2b/3a guy tends to be bigger than the gap between a true 1 defender and a number 4. Matthews has also already proven himself as an impact player at 19 in the NHL, while young defenders tend to take awhile to find their footing. For example, Tavares has been the better player than Hedman for a significant portion of their careers, only for Hedman to recently pass him. Same can be said for Doughty/Stamkos. That tends to make them more high-risk and long-term projections. You get more value out of forwards on their ELC's.