“Hunter gatherers required lots of land, and this limited the size of the tribe to what could be supported by the food within a reasonable walking distance from the camp. Camps also had to move frequently as hunting depleted the game in the area.
A farming community could sustain a much larger tribe size in a given area, and thus could muster a much larger number of fighters to go after any hunter/gatherer tribe which tried to encroach on their territory.”
Good points BUT humans are built for the Hunter Gather lifestyle. Can move 20+ miles a day if needed, only humans and some Equines can do that. Once you get Dogs and Horses you get to the Mongol Empire.
Healthy young adults can move 20+ miles per day. Pregnant women carrying toddlers and older members, not so much.
More reasonable would be to move a mile each day, while hunting parties range several miles in either direction perpendicular to the path of migration.
No-one was penetrating the deep steppe until horses were domesticated and could haul enough supplies to operate there.