I have a number of athletes who come to me with overstriding issues. They can also power clean 140kg and full squat 450lbs.
Overstriding is a technical emphasis problem that is exacerbated by lack of strength. The weight room will not fix it. A good progression of technical work, drills and appropriate sprint workouts will resolve overstriding.
Just because someone has a website, posts “impressive” credentials and can offer products, doesn’t mean they know what they are talking about.