While I beleive the use of such level of force is not warrented, the rancher is the source of the problem here.
It is not his land and he has not paid the fees to use the land. In other words, he is squatting on the land with his cattle.
I fail to see where the rancher has a legal leg to stand on.
If he is correct that his family has used that land since the 1800’s, then he has standing, the same as right of way.