Really, the thing is when you loot a region, (or is under 'local' hunger), the people would not to die in enormous amounts, but to flee to neighbour regions (or hide in the woods), and come back to their region when the situation got better. I can understand destruction of production, or even the destruction of a City, but usually the people is hard to exterminate... they usually don't wait for death but flee! 
Maybe this would be a bit more realistic and better for the game.
Errr... you need to read up on history. Starvation was a huge killer in the dark ages, and generals back to biblical times regularily put entire towns to the sword.
