@DukeEgr93 One way you might be able to divide up the enrollments that you already have (likely created by your institution's student information system) is to give students secondary enrollments in custom sections. If you have permission to add sections in your course Settings > Sections tab, you can use the People tool's +People button to assign second enrollments in four batches. You could get a spreadsheet showing all students' Login IDs by exporting the Gradebook. Then decide who will go in Subsection A. Click +People, select the ID type you'll copy from the spreadsheet, select the correct role and section, then copy and paste all the relevant IDs, click Next, and Confirm. Repeat for the other sections. This could be less work than using Edit Sections for every student.
Caveat: I don't know if Gradescope will work well when each student is enrolled in the large section and a subsection, but the subsections could be useful filters in Canvas Grades and elsewhere in Canvas.