Mathematics helps here, too. Game theory to be more precise. Of course, lots of the solutions to fair distribution problems have been discovered before mathematicians got a chance to invent game theory. For two people, the you-cut/I-choose procedure works.

For lots of people introducing money is more efficient: just auction off all the plots to the highest bidders, and distribute the proceeds equally. Auctions are a great way to convert subjective valuations into fair numerical valuations.

See eg things like https://en.wikipedia.org/wiki/Shapley_value or https://en.wikipedia.org/wiki/Fair_division