“Focusing on one specific region – that just so happens to have a climate suitable for both foraging and farming, and preserving human remains...”
So how do they know there was a genocide? How do they know the hunter-gatherers didn’t just move on?
A group of farmers is always larger then a group of HG's because farming allows you to have more people on a smaller amount of land.
So 30% to 70% would be about the right mix.