The Display Names in Dynamics 365 are stored in the Full Name field (of Contact or User for example), and are based on the data that was entered in the First and Last Name fields.
You can control how the display names are displayed to a certain extend, but not including titles and salutations.
If you go to Settings -> Administration -> System Settings, in the General Tab you will see the Name Format option, where you can select one of 8 options for the name field. This is configured across the board, so will be for users, contacts, etc…
If you need to display name to still be different, you can either create a custom display name field, and using a workflow possibly append the different values to make it up, or you can try doing the same with the full name field using a workflow or a plugin.
Hope this helps.
