AEO - Need some clarification

I have been on a Post graduate work permit since June. Although I graduated in GIS-Geographic Information System, I am presently working as an Account Manager of a Facility Management Company. I was hired because of my previous experience with managing client relationships rather than the field I had graduated. My employer has agreed to file an AEO to HRSDC toward my PR under the new rules. My previous experience acquired in my country is under NOC 4131 and I have been in Canada for the past three years as a student but have been with this employer since August 2008. As such, can my employer file an AEO in my favor? I am worried that HRSDC might reject it because my present job is not GIS related. Also, Does my employer really need to file for an AEO or an offer of employment stating duties, requirements and responsibilities on Company letter and seal will do? Any views about this. Thanks!!!