Ditto, or changing "ID Number" to username. Or adding it as an additional column.
For our purposes we will only ever be using Assignment as a marking tool for physical activities, there is no security issue with having the username onscreen as the username in this case is their ID Number as it were, but ID Number is not populated when the users are created (no functionality to do this). The assessor has the username on hand, but there could be a dozen "John Smith"s being assessed.
I'm reasonably handy with modifying code and using the $USER object, but haven't been able to track down where exactly the table layout is being generated, and where its content is being drawn from. When marking, the URL is "/mod/assign/view.php", with an "action" of "grading" appended. Possibly going to view_grading_page(), maybe using gradingtable.php to render?