Oh, I don't mean conflict with other Neanderthals. I meant conflict with Homo Sapiens, who by all accounts seem to be much more comfortable with larger group s

Oh, I don't mean conflict with other Neanderthals. I meant conflict with Homo Sapiens, who by all accounts seem to be much more comfortable with larger group sizes, and aren't cold-adapted. Yes, violent competition isn't conducive to low population densities (especially in an environment as unforgiving as the Neanderthals') but that doesn't mean another larger group couldn't invade. After all, changing "humanoid" group sizes (aka "Culture") would take much longer than the introduction of the Holocene.