All I see is that he is recently been given to you as your lieutenant. So a Smoker/Tashigi type deal perhaps? They also could have asigned him to you because, while dserving of his promotion, they question his attitude in the field the way he mentioned in his history. And he was specifically assigned to you because of your reputation they believe that you can control him and hopefully teach him as a marine? Or you could have requested he join your crew for that same purpose?