I had heard that there were several waves of migration towards Europe, do we have a better estimate about this? Wouldn't multiple waves over time provide more diversity?
for the out of africa group i've seen sizes from 100 to 10,000. i used 1,000 to 10,000 as a likely moderate number, and the range also points to the census size being larger
we can assume that conditional on the size of OoA the other groups were way larger (10x or more). otoh, the main thing i did not explore is that i am now believing that africans themselves especially agriculturalists are 'compounds' of various bottlenecked groups (why west africans are closer to eurasians than they are to khoisan)
i think this is probably an overestimate tbh (assumes poisson distribution of offspring).
Either way, my understanding is that all indications point to middle and late Pleistocene populations being highly structured and "unusual" as far as standard assumptions go.
One thing that should be made very clear is that ancient population structures generally don't map neatly to modern cultures or languages. It's best to treat modern terms as labels of convenience.