is it possible for a non-manager employee be assigned the Performance document for a peer employee?

When using the Performance Management process to create Performance Documents, is it possible to select the Manager Selection Method of 'By Manager ID' and assign it to a non-manager employee who is being requested to perform the review of a PEER level employee?

For example:

Employee B and C have no direct reports and report to Manager A.

is it possible to create the Performance Document using the 'By Manage ID' Manager Selection Method, by entering Employee B for the Manager [ Manager ID field on run control], and making Employee C the Employee to process?

Or does the individual being selected as the Manager for this document creation have to be a manager?