Yeah it is very right question whether the Hiring Manager really knows what actually he or she wants from the new recruit. I have got to experience the very same circumstances in my professional life and talking to hiring manager, what exactly they want from the candidate ant they were not very clear about the job nature what they are going to offer. They just go for hire & hire without thinking whether the candidate fit well or not or resulting in higher attrition and less job satisfaction. Also even not understanding differences between Manager & Supervisors as you rightly pointed out at least in INDIA I have seen it in many company.