Let him stick with DQ. It's his passion, his life's work, his brainchild, and his baby. Besides, he's a busy enough man as it is. Taking on responsibility for the other major JRPG brand would be too much. If you want FF back to it's roots, bring in Hironobu Sakaguchi. He created the series, and would probably still be in charge if not for the FF Spirits Within movie debacle.