Pista is traditionally led by a military figurehead, given its importance as a border town. Given its barren landscape, however, the city relies on imports for food and other goods - imports that are paid for by taxing any trading caravan that passes either north or south.
Thus, while the ultimate authority lies with the Commander, they hold court with the Keeper of Coin (the official in charge of taxation) and the Merchant Council, consisting of the lead merchants of the city, as they represent the business interests in town.