We'll create fresh WordPress site with Overwrite Author Name installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Are you currently giving multiple users the same login details?
‘Overwrite Author Name’ is a plugin to ensure when publishing a post the author name will be replaced. This allows the site to have a consistent/clean authorship and protects individual users from leaving their user-name as author. This is important as users can then login with their own user-name/password using capabilities allocated, however the published content will have a corporate author name against site content.
For increased security the user account used for the corporate identity should also be given minimal access to the site (e.g. the Subscriber role only). In this way should someone crack the public facing account password, using the user name, they will only gain subscriber access.
supports standard and custom post types.
http://justinandco.com/plugins/overwrite-author-name/
https://github.com/justinticktock/overwrite-author-name