Requisition heirarhcy issue

 hi Experts , at out client the OU is same but at the same we have to diffrent heirarhcy of Requisition based of the department ... now one heirarhcy has diffrent authority and another have diffrent authority to give approval though few peoples are same ...... now my question how doest to two diffrent heirarchy work at the same time ....

as i solution i am thinking to make a 2 diffret heirarchies of requisition based on the client and assing on of them (which is most regular ) in the document type and the and to do personalize the data entry for other heirarhcy of requisiton ..?? kidnly help me in this issue