Agreed, Scheifele being a good defensive center would probably solve this.
At a certain point, defense isn't just about effort either. It's a skill to be able to mentally read the game. As Scheif approaches 30 you have to wonder, is he pretty much what he is now?
It's not about dropping responsibilities, it's about having support around your best players.
What is the best way we can support the weak points in his game and still enjoy the production?
If the solution is to keep Connor and Scheifele together and continue to develop their two way game with each other? Maybe if that does work out that's the best version of the team.
The issue is even Scheif doesn't get a ton better defensively, we are sending out the same bottom 5 top line in the NHL we have been instead of one that is measurably better.