Hi @JamesRong,
I don't think this is going to be an easy task. As things stand right now, grade scheme use and creation in Canvas is tied to the "Grades - Edit" permission. You certainly don't want to take that permission away from teachers as they wouldn't be able to grade. In some cases like this where more customization is desired, it's possible to use CSS and Javascript as part of your account/subaccount theme to hide or change how things display in Canvas. Grade schemes some into play in so many different areas of Canvas (course settings, assignment settings, quiz settings, etc) that unless it's super important to lock down, I don't think I'd go down that road because it will be complex to start with and you'll need to continuously monitor for changes Canvas mades and adjust customizations accordingly.
I hate to say this, but I think it's more of a faculty training thing on this one. You can definitely set up schemes at the account level, and then just tell your faculty that they need to pick from one of the schemes. It's not perfect by any means, but something to think about.
If you'd like Canvas to separate out the permission to create grading schemes into something more granular that you could disable in the future, you could submit that to the Ideas area for consideration.
Sorry there isn't better news for you on this one.
-Chris