I'm not an anthropologist or a historian, but AFAIK it's common for tribal societies to have largely "ritualistic" battles over small territorial disputes. There's little to no killing* and one side agrees to be the loser**, conceding the land and moving somewhere else. This makes sense when societies aren't (at least fully) sedentary and the squabble is over some pastures or hunting grounds.
*Zulus before Shaka allegedly just threw spears towards, not even AT each other.
**Presumably based on the number of combatants and weaponry each side has, posturing how severe pain they would dish out in an actual fight. Showing up with 10 dudes and refusing to concede when the other tribe brings 100, would probably get you killed.

