A government class could prove to add to the gameplay quiet a bit. For example a ruler could give certain benefits to the town depending on his or her strengths and weaknesses, a strong bodied ruler could give defense boosts to the army, a strong spirited ruler could give healing boosts to healers and and speed boosts to farmers, a strong willed ruler can give efficiency boosts to crafters which can improve a crafter’s chance of crafting fine items. The ruler could start off as a petty duke but rise to become a powerful king based on his or her level, the net worth of the town, and the population.
Side government classes could be good also, such as generals which would be an upgrade to the knight, bishop which would be an upgrade from the cleric, and the noble which could advance from the tailor or maybe have new precursor classes for it. The general can provide the army with a bonus to it’s attacks, the bishop can advance the healer’s healing abilities, and the noble can speed up production of various crafters.
Rulers and the government classes can reside in some kind of castle or some kind of government building.