Yeah, no. He wasn’t stealing anything.
Taking something that does not belong to you is stealing.
If you go to someone else’s land and take their hay bales to feed your cows, you are stealing. Letting your cows graze on land that you do not own, that you have not paid to for the right to graze there, is taking the fodder and feed from that land and that land owner. That food has value and could have been sold to others via grazing fees.
Bundy was taking something that did not belong to him, from land that he did not own, without permission to do so. That is stealing - period.