The situation appears to be
Family farm - 3 brothers. All three brothers help out on the farm through their teens and and early twenties as is fairly standard on family farms
Two of the brothers eventually go off and forge their own careers, usually trades or something connected to farming still however loosely.
The brother who has decided to remain on the farm (often the oldest but not always) eventually goes into partnership with his parents. At some point the older brother negotiates a move into the main farm house with his family or for a new house to be built somewhere on the farm for either him or parents to live in.
At some point brother becomes the main partner as parents get older and parents stay in the partnership for tax purposes but in reality semi retire.
The other brothers get married etc/ have their own families and look at brothers situation in comparison to theirs, big farm house, lots of land, an asset that on paper has a huge value. They feel that it's unfair that their brother will likely have all of this handed over to him (often ignoring the huge sacrifices and responsibility that comes with being the next in line to the family farm)
For the brothers to get their 'fair share' it will mean selling land or having to find huge sums of money out of the farm business. This will likely lead to the break up of the business and generations of hard work being undone.
A lot of farming families try and plan for this by supporting the non farming siblings to buy houses etc but it falls apart if one non farming sibling still decides 'its not fair'.