Tuber farmers who can't do anything but eat the day's harvest get by on much simpler culture than grain farmers. Landlords with granaries? Tubers can't be store

Tuber farmers who can't do anything but eat the day's harvest get by on much simpler culture than grain farmers. Landlords with granaries? Tubers can't be stored, so the idiot building palaces is wasting time. Kings and armies marching to claim faraway fertile lands? Rich city ruling over neglected grain basket region? They can't eat anything from faraway land. Festivals, astrology? Those won't help for perennial crops. Accounting? Not helpful for food.