If there are no long term health concerns with Karlsson, and we know he will sign long term here, I give up Draisaitl + without a thought. It has nothing to do with Drai. I love the player.
Detroit - Yzerman and Federov. Datsyuk and Zetterberg. Those players made the team really good. Lidstrom made them a consistant cup contender.
Pronger - In his prime, every team he played on had a shot at the cup. He carried 3 different teams to the finals.
Chicago - 3 cups with Kieth
LA - 2 cups with Doughty.
Karlsson and McDavid on the same team = Guaranteed Cups. Its as simple as that. If you can make it happen, you make it happen.