Danda symbol is not just invention but in Hindu text, kingship is symbolize by stick. In Buddhist textyou can find chakras as a symbol for kingship, so, king is supposed to be righteous king, Dharmaraja who follow universal dharma. There are various dharma, not just one that teach about what should you do. In Buddhist context King should try to avoid the bad thing as much as possible, unlike Hindu that politic are important than morality.