Zion is one of a billion. Maybe one of seven billion. I wouldn’t use him as a comparison point for anyone, and he’s hardly the only player with injury issues. Jon Issac is a beanpole and he can’t stay healthy either. Some guys just can’t stay healthy no matter what their body composition is.
Certainly would not consider myself an expert trainer, but I do think people are overplay the “fat” angle with Zion and its role in his injuries. The idea that he would just be fine if he lost weight isn’t correct imo, and Saint is probably onto something with the constant dieting. When you’re on a deficit, recovery is worse. That’s just biology and even though Zion is an alien it applies to him too.