I looked at the User Profile Fields to see if you can make your own name field for lastname / firstname. You can create a custom field in the firstname / lasname format; however, it appears the Browse list of users does not include the Custom Profile Fields. If you can get the Browse List of users to show the Custom fields, the you can add the names of the students in that field and view it accordingly. Unfortunately, there does not appear to be a work around for the existing First name / Surname field without editing the core code in the site admin. It would be nice if there is a work around.