Ok, this is going to be a long one. I come from tribal culture. My tribe name is Cuce. And i am Serb, Europe, Balkan peninsula. We were under the rule of Ottoman Turks for centuries and my ancestors had a miniature free enclave in the empire (it remained mostly by being a minor nuisance than a real threat to the empire). That being said, here is about the tribal culture: 1. Tribe is all. There is no other allegiance but to the tribe. No nation or religion comes before the tribe. 2. Laws are cruel but fair. And no one is above the tribal law. 3. Duty to the tribe is paramount. Every able bodied male is a warrior. Units are based on near family->extended family->tribe. Every unit has a leader who is democratically chosen among the warriors. You only obey vertically, not laterally. (you can only have 3 officers in line to command you, one is your father/uncle, second is family leader and at the end a tribe leader) 4. Duty to the tribe is paramount. Every woman is to be a mother and bare new generation of warriors. That guarantees tribe survival. Male children are more desired because men die young. If you have one daughter she will live long enough to have children. If you have 5 sons you have a guarantee that one will live long enough to have 5 sons. 5. 164
Every one has a power of making a decisions in their area of duty. Men make decision regarding things outside of house, women regarding things inside the house. For instance, new bride is chosen by oldest woman in the family, since woman will have to live with her (men are mostly not inside or around the house, it is their duty to provide). 6. Age of manhood/womanhood is 15 years. Men start practicing with weapons at the age of 7, sometimes even earlier. 7. Tribe doesn't have multiple types of units, since it is family based. They are all same kind (horsemen, infantry). 8. Their tech is of same level as their enemies but of lesser quality and numbers (since every family is arming themselves). So no canons or artillery. 9. Their attacks are quick, brutal, devastating and very personal (eye to eye). If they don't win on the first attack they retreat. Never give opponent the opportunity. 10. Catching them of guard is not possible, someone is always watching. 11. Women are collecting the dead and wounded. Also bring food for warriors if they are defending. 12. when defending they dig in and do not retreat. They only defend their homes not the conquered lands, those they just leave and return later.
These are some rules that you can use to build the tribal culture. Stoicism is also prevalent way of thinking about life.
This is taken from history of my people but from what i have read it is generally applicable to most tribal cultures.
If you want to learn more i can write about some aspects of daily life you may be interested in. Or tactics used by my ancestors (these may not be applicable since it involves a local geography and specific weapons and armor) 164