Mulan and Pocahontas have traits and qualities needed for that sphere and are most likely to succeed in that departement, Pocahontas due to her wisdom and experiences (she traveled to the other side of the world for entirely political purposes and managed to prevent a WAR, twice, both in the original and the sequel) and Mulan and Shang could make a couple of good rulers due to their knowledge and ability to effectively protect their country.

Or Mulan, or maybe Jasmine.

Or Jasmine or Pocahontas. Maybe Tiana.

She does it much quicker.