Thank you all for your replies !
As I know my professional recommenders quite well, I have insisted with them that the most important thing they needed to emphasize was my ability and eagerness to pursue research and they believe I would fit in the academia world. I have told them that they should adjust my reference letters for the academia world and not for an MBA.
Asides from my relatively average GMAT score and the
LORs, I have spent extra time searching for the right universities with the right teachers for me. Indeed, I have clear ideas of the OB/HR subjects I want to research and therefore have been insisting on that in my
statement of purpose and in my university search.
Again your advice on these and on my profile is more than welcome !