To understand the "logic" of this appointment made by Francis on May 21, 2017, you must read the sermon Francis delivered four years earlier on May 21, 2013.  There, he said that, according to the "logic of the world", a "promotion" is when someone is given more power or a cushy job, but that the Church must reject the temptation to look at authority in that way.  Authority in the Church is not about what dicastery you get to lord over or how many years you will get to serve in your new plum assignment.  Authority in the Church is about service, and if it means serving as the number two in your third world archdiocese, as long as you are faithfully serving the Lord and the poor, there is no greater glory.