I suggest utilitarianism versus Kantianism. It's a standard opposition, so in
tackling it you are getting well into established ethical discussions. Mill did say in ch. 1 of 'Utilitarianism' that the practical working out of Kant's theories involves an appeal to consequences which grants Mill's own, utilitarian position. However, if correct, this would only show that Kant and Mill are capable of reaching the same conclusions, not that their routes to those conclusions - the philosophical pathways - are the same. I doubt if Mill would have denied this.
An after-thought : the appeal to authority and cultural relativism can connect, and any clash between them avoided, if the authority is one that is (de facto, only) culture-specific, recognised as an authority only within a culture or set of cultures.