The best option then was to introduce new jobs and opportunities that the locals could do in the meantime.
However, they also needed to ensure that the people would be willing to return to farming again. Or else, the food supply in the said territories would dwindle if the farmers greatly decreased.
Likewise, they cannot simply meddle in the territories' overall management since the other nobles would fear they were using the disease as a way to remove more power from the ruling households.
Thus, they had to make it clear that whatever they would introduce now would only be temporary.
If the work is likely to last for long, it has to be from something already possible in the territory itself, only expounded.
This way, they could get the nobles to cooperate as well by making them part of it.