We'll create fresh WordPress site with SF Author Url Control installed. You have 20 minutes to test the plugin after that site we'll be deleted.
With this plugin, administrators can change the default author base in the registered users profile url, and the author slug of each user.
Changing an author slug is a good thing for security (if your login is “This Is Me”, your slug will be “this-is-me”, a bit easy to guess).
The plugin adds 2 fields for this purpose, one in permalinks settings, the other in a user profile.