I wouldn't mind scorched earth if it had sensible consequences. But it doesn't. It's a no-lose strategy, because it takes days without food before penalties really kick in, and by then you probably already lost the region or are about to. Then, once the conqueror finally gives food, it takes many days before the penalties stop. It just doesn't make sense that the locals love those who starve them and hate those who feed them, which is what the current system is. You'd be stupid *not* to drain the region of food, as it is.
Checks would be needed to avoid this gamey no-lose strategy. Either deny access when there are hostile troops in the region, or when there's a takeover. But if it's the latter, then I think the invading army should be able to know the region has no food before starting the takeover. This way, if the defended starves the region, the invader always just has the option of going "oh yea? fine, we'll go take that OTHER region, thanks for starving yourselves for nothing".
