Difference between user_login and user_nicename

Hello.

Is it possible to have user_login, user_nicename and display_name in wp_users the same? Or at least user_login and user_nicename the same.

The problem is that users need to login using login name, in their profiles and in BuddyPress @mentions they have another name, and finally users see their display_name in links to user profiles.

3 different names at one site it’s a lot… Can we set them the same?