If you understand another culture or individual's logic, you can avoid violence or even manipulate it. If you don't, you can precipitate violence that would never have occurred in your own culture.
The exercise (which will be laid out in the Drills book, by the way) begins with choosing a neo-lithic base, either as a farming community or hunters.
Marginal societies live closer to hunger than most of us can imagine: a bad hailstorm or a wildfire can change the balance enough that many of the tribe will starve over winter. Most systems of preserving food were unreliable and climate specific, before modern refrigeration and canning (with the exception of distilling).
So, the first question- what does your society value and what can society not tolerate? Skills, from basket weaving to pottery to making arrowheads are critical. Farmers need endurance; hunters speed and strength. How do you encourage this in children, what do you reward?
And not tolerate: when people starve, do you tolerate those who don't work? Those who steal? And how do you punish them? Death? Banishment? Pain? Humiliation? Certainly not incarceration. Who would agree to feed a non-working prisoner when four hard workers starve each winter?
The class comes to consensus on these, and so long as they are reminded of certain things (like there isn't unlimited land or resources, other tribes live on your borders) you can see echoes of what the writers choose in history.
Then the hard decisions come: You are done. Out of resources. Your tribe will not survive this winter unless you violate borders or attack another tribe or subjugate a village.
You decide what you will do so that you do not see your children starve, and then you decide how to do it. Somewhere in the mix of the culture already established (fierce, long traveling hunters, peaceful people drifting through acorn lands, or tough farmers who will not yield, or....) and the need, they will pick a victim.
The decision is cold, what will get the most at the least risk. One of the options of potential territories to invade includes a tribe known for cannibalism. No one ever suggests attacking them.
That mix of who you are and who you choose to attack will drive a very logical analysis of how to attack. This is for food, not for honor. It can trigger revenge and if you lose too many people you will be helpless. The students will strategize and they will strategize well and safely. They are writers and peaceful people, but this logic isn't new to humans, not by millennia.
This, incidentally, is one of the things I hate about most fiction: our society has not been marginal for some time. When we fight it is usually non-lethal, fun and over matters of social status (the Monkey Dance) or pride or honor (dueling). That has it's own logic: a contest of skill and social aplomb, with an audience. Lethality of the process has steadily decreased over time as we have come to value life more. All of that is not only unheard of, but counter-productive when applied to the violence based on the logic of hunger. Authors who don't know the difference (and I'm not even sure my beloved George MacDonald Fraser really got this part) frequently do fight scenes that might not be bad, but are stupid...and for me that is worse.
Then the fun part of logic-- after teaching all of your children that it is a good thing to shoot arrows at a squirrel but a bad thing to shoot arrows at their siblings, the children are going to ask some questions when you bring home some grain and meat and clothing and weapons of another style, all still dripping blood.
You'll have to explain to the children. More, you will have to teach the children to do what you did (just in case, sure, until someone notices how much easier raiding is than farming and how slaves give you leisure time...). You will teach them how to do it and you will teach them to be okay with it...
Part of the logic of violence in any culture is why and when it is allowed...and why and when it is necessary. I hesitate to say that religions start here, with trying to excuse the first major violation of ethics... but I have a gut feeling that at the very least the stupid parts of religion start right here.
And once these excuses are in place, once the rules on when violence is demanded are established, what does it take to change them? We all have come from societies that at one time were hungry and we have things written into our laws morals that date from those times. How many of them have we kept even though we are no longer hungry?