This is absolutely bananas. Casey has nowhere near the physical stature Dahlin has, Casey did not spend the last season playing in a league against grown men, Casey will likely only get 3rd line minutes, and Casey plays in a league that is, much more contradictory to what you're saying, much harder to adapt to than the SHL is to over here. You act like Dahlin has never played on a smaller ice. You also act like Dahlin isn't quick, physical, or smart in a very rare way.
If you honestly think Casey Mittelstadt will have an easier job, coming from a shorter and less physical NCAA season, than Dahlin will coming from a longer, more physical season, because the ice is 10ft smaller, you're out of your mind.