The usual tribal conflict pattern is to seize territory as a hunting ground. Note that for nomadic tribes, there is no village and therefore no fixed location to raid.
E.g. the Comanches had a longstanding war* with the Apaches not because they wanted to seize each other's grain stores, but rather because they wanted control of the best buffalo hunting grounds.
* Not a war in the sense that we'd call it today. There were e.g. no organized charges, battle lines etc. Maybe "long slow series of irregular cavalry skirmishes" is more accurate than "war."
E.g. the Comanches had a longstanding war* with the Apaches not because they wanted to seize each other's grain stores, but rather because they wanted control of the best buffalo hunting grounds.
* Not a war in the sense that we'd call it today. There were e.g. no organized charges, battle lines etc. Maybe "long slow series of irregular cavalry skirmishes" is more accurate than "war."