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