Jack Han has a pretty interesting article up on his newsletter about the critical weakness in Galchenyuk's game, his poor dynamic skating posture. What is really interesting is that Jack worked with the Leafs and thus has some insight into how the Leafs will attempt to rebuild his posture and certain muscle cues. Unfortunately his past knee injuries, age and genetics (ankle flexion, t-spine flexibility etc.) may place a ceiling on how much he can actually improve, but still a worthwhile read and an interesting topic that most casual fans are unaware of.
https://jhanhky.substack.com/p/searching-for-alex-galchenyuk