He can. The regulations recognize a manager of an essential function operating at a senior level, as well as a personnel manager who supervises professional or supervisory staff. What he cannot do is rely on a senior title while personally performing the function he claims to manage.
Managing a function is a real category, and a demanding one
Hypothetical example: Bartholomew directs operations for an East Ferris modular-home manufacturer and is being sent to open the group's American plant, where for the first year the only other employees will be a site foreman and two assemblers. Neither is professional or supervisory, so a personnel-manager description is weak. The function-manager route asks different questions: which function does he own, is it essential to the organization, does he operate at a senior level within it, and does he hold discretion over its day-to-day operations.
Production planning and supplier qualification for a manufacturer is essential on any reading. The evidence then has to show that he sets the plan rather than executes it — purchase authority to a stated limit, the right to approve or reject a supplier, sign-off on the production schedule, and somebody else physically doing the assembly. Where he will also work on the line in the early months, the petition should quantify that honestly and explain why the managerial duties remain primary.