It’s easy to sort the list of users or groups by name, account name, or ID.
Name refers to the user’s or group’s full name, and account name refers to the user’s or group’s short name. The ID is assigned to users and groups when they’re created. Recently created accounts typically have higher IDs than older accounts.
In the Users or Groups pane of the Server app, Control-click a user or group, choose Arrange By, then choose an option.