Lets call that next door neighbor farmer C. Shall we?
Farmer B and farmer C both inherited their land from Farmer Sr, who is both their fathers. Despite Farmer Sr's attempts to be fair, B and C squabbled and quarreled as they always had since their childhood. Farmer Sr tried to help farmer B and C work it all out, but as soon as Farmer Sr. went on vacation, farmer C attacked farmer B, because he wasn't happy with his inheritance. So farmer B had no choice to beat down C, which has made farmer C quite resentful of farmer B. Then tragedy hits. Farmer B is struck with a horrific drought which cases hundreds and thousands of his cattle to die. Farmer C decides to kick him when he's down, texts messages his buddies (Farmers E, F, G, and H), then they descend on farmer B's property with fury. Fortunately, farmer B raises a mighty pitchfork and whips their asses into oblivion, but is merciful enough to at least leave them some little morsels of land to live off of. Now farmer B has always been kind to farmer A. And farmer A also has little desire to do business with farmers D through H either. Since all farmers C, D, E, F, and H, are all quite hostile toward farmer A, A feels no particular obligation to sanction B when he takes measures necessary to control farmer C in particular.
Since then, Mr. Farmer Sr has become a withered old man, who can do little to A, B, or C, except scold them. And they laugh in his face when he tries, though A does pay his old man medical bills to keep his respirator and wheelchair working correctly. As the relationship between farmer A and farmer B has blossomed over the years, B has helped keep an eye on C-H, providing much needed to surveillance and intel for when situations that might threaten A were on the rise. At times when X, Y, and Z also planned to harm farmer A, B took up arms and stood against them when there was anything he could do to help.
A and B are close friends to this day. Though they don't always agree on things, and both are far from perfect, they strengthen each other through sharing their technology, education, and industry. At times A has been the stronger of the two. Other times, such as now, B has taken the lead with far greater wisdom, character, and resolve. Even winning the hearts and respect of many of Farmer A's workers, or at least the ones who come to know their stories.