Can a non-exempt employee manage another non-exempt employee?

Yes, it is entirely permissible for non-exempt employees to manage other non-exempt employees.

Employers are under no obligation to classify employees as exempt, even if they meet the Fair Labor Standards Act criteria. Employers may have an entire workforce of non-exempt employees if they wish. It is imperative to ensure that they are paid for any overtime and follow other wage and hour laws applicable to non-exempt employees.