360 Degree Performance Document- Not able to enforce number of participants required.

Summary:

We have enforced the minimum number of participants of five in the 360 Degree Performance Template, still employee and manager are able to add and send request to less than five participants. What should be the workaround for this?

Content (required):

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

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