Population density was extremely low though. So imagine it was tough to form large communities and most people mainly only had contact with people within their group and maybe a few others living close by.

From that perspective I find it hard to imagine that neanderthals would be treated that much differently than other outsiders. Well unless they behaved significantly than homo sapiens when interacting with other people..

maybe not the most ethical and objective analogy but dogs and wolves within the same pack seem to get along much better than they do with wolves from other packs. So I’m not sure species would be a huge issue in very simple communities