As I understand it (and I don't understand it, I'm not source of authority here) the tractors don't need to work day and night, they need to work during the imp

As I understand it (and I don't understand it, I'm not source of authority here) the tractors don't need to work day and night, they need to work during the important planting and harvesting seasons. That happens to be the same time that your neighbour wants to do it. Efficiency is key here so that one harvester can work several farms 24/7, for a limited period of time. As you outlined, uptime is critical during these periods. I spent a lot of my time in remote locations, and reliability trumps everything. The cost of a hotshot is significant - however I was far more remote than the farms where. Paying a person to drive the tractor doesn't seem like it's the large cost. It's the machinery you need 1x per year, at the same time everyone else does.