I think what I'm getting at is - how settled were they? Mobile hunters could certainly bury their dead and erect cairns. Coming back to the question of scale and the concept of "temple" building, that seems to require a settled population rather than a nomadic one. That means a regular, local and dependable food supply surely. The alternative is to envisage a settled group of temple builders being fed by roving bands of hunters who would have to go further and further afield to find game - and then bring it all the way back to the temple site.

Before agricultural farming, the interim stage is bridged by herders and/or fish-farmers who manage the food source rather than chase or gather it.