it is not just farming land that is valuable, sometimes there are good fishing spots and etc in scarce regions. However those are far rarer situations and usually there is plenty of food for everyone, but hard times also happen and then most animals and humans practice mutual aid.
There is a good book about it, by Kropotkin, called Mutual aid. It isn’t long, I listened to the audio book.
You can point to territorial disputes between non-agrarian humans to suggest otherwise
Hunting grounds and shelter were more important than mutual aid
You don’t even need to use humans, you can use other primates
it is not just farming land that is valuable, sometimes there are good fishing spots and etc in scarce regions. However those are far rarer situations and usually there is plenty of food for everyone, but hard times also happen and then most animals and humans practice mutual aid. There is a good book about it, by Kropotkin, called Mutual aid. It isn’t long, I listened to the audio book.