I agree that any group of people will eventually have some form of conflict but I don't agree that a hierarchical structure is the only way to resolve said conflict. You could just as easily apply any of the methods of governance that humanity has devised to resolve a conflict so I don't think the method of governance is crucial to the resolution of conflict. I think that getting both parties to agree to a satisfactory resolution is what is critical. That can be done with force as in a hierarchy where an external party enforces a resolution on both conflicting parties or it could be done without outside intervention, this obviously happens all the time in a variety of situations.

Ideally, every conflict should be able to be resolved directly by the people involved without additional harm being caused. Maybe there is a way through education or other tools that we can build that would allow people to resolve any conflict in such a manner? Maybe prevention is the best remedy and there exists a way to defuse conflict before it reaches a level that cannot be easily resolved. My point is that resorting to authority or force is not the only solution.