As to resource warfare, it's a non-starter for most foragers. You walk away, or you strike an agreement about the use of lands. There are conflicts anyway, but they're infrequent -- the incentive isn't present to justify a bloody battle most of the time. And it doesn't come up as often as you think, either, because as I've stated, forager populations don't grow as quickly (they tend to stay around carrying capacity when different groups are summed over a given area) and indeed, devote active effort to keeping it that way, which supplements the tremendous passive biases in favor of slow growth.

Where it does come into prominence is with low-tech agriculturalists, pastoralists and horticulturalists. Those people have something to fight over (a stationary, vulnerable or scarce landbase, that rewards their effort with high population growth and gives incentive to expand or lock down an area for their exclusive use).