How many grade rates can be tied to a single grade?

Summary:

I am putting together a quick reference guide for implementation for myself and found that my organization has many grade rate's tied to a single grade and I am not sure if that is correct.

Content (required):

I always through grade rate and grade were a 1:1 relationship but at my organization, it appears that for single grade there are at least two-three grade rates tied to it. Is this going to cause an issue?

I have attached an image of my example.

Version (include the version you are using, if applicable):

22C

Code Snippet (add any code snippets that support your topic, if applicable):