True. Each crew harvesting wheat requires one person to operate the combine; one person operating a tractor pulling a grain cart; and at least two persons driving a trucks/grain trailers back and forth to the elevator.
Depending on factors such as how good the yield on the wheat and how good the access to the field with semi-trucks, and the length of wait at the elevator, you may need an additional tractor/grain cart.
Along with those people, a crew will usually have a person or two that drag around the fuel/grease trailer and other necessities. As compared to say ... harvesting produce ... wheat requires very little in the way labor, but the labor needs to be skilled. The machines and other equipment are extraordinarily expensive to buy and maintain and we don't let low-end labor around an operation such as this.