Currently, the data import for student test scores requires the student_id field, but this field isn't included in data provided by either ACT or the College Board. Basically, you are requiring schools to put substantial time into editing this data before it can be imported. As it stands, this import is basically useless.
We use the import by student ID all the time. If you use the CONCATENATE function in a spreadsheet to combine the first and last names into one field, you can then use that field in a vlookup to match up the student_ids to the student first/last name combo. What I just described takes a couple minutes do and it significantly reduces entry time. I would be leery of using a first and last name option for importing since we have students in our school how have the same first and last name. Student IDs are always unique and a much better individual identifier.