Based on reviewing the process and procedures:
it seems unnecessary to collect GitHub usernames. Instead only the email should be collected, and requestors should be made aware of best practices, i.e. link a single GitHub account to multiple email addresses instead of creating multiple GitHub accounts. By doing so, GitHub Organization Owners only need to have an email address to send the invite. To follow (or not follow) the best practice, is then up to the requestor.
In light of that, Index.md should be updated to: