O'K' Let's take your example.
Firstly I say this, if you are arguing then you and indeed both parties are already out of harmony in yourselves.
This is the first and most important point to realize. Spirit and mind in harmony has no argument, is calm, not upset, happy and fells good.
Secondly there is a situation and the one you describe is who owns the land. You must find the path which leads to the resolution, just like the circle in Aikido. When both parties, being of sound and calm and amenable disposition (in harmony with themself) agree on a path, a course of action and are happy with it and whatever the result of such a path would be then they have found the 'circle' Harmony. It would probably take some discipline.
How would you go about someone claiming your land apart from walking the "circle of aikido?"
I feel you are being a bit vague in your responce ?
Itīs easy to talk about harmony but actually achieving it in a situation of conflict is a different matter.
Agree on a path: How ?