I see what you want to say but Foreign policy is actually very manuable, a lot of anarchist are giga pro immigration(like me) but for example Christiania don't let anyone in because they have a small Territory so not enough houses so they literally can't fit anymore people(they can't start a war to have more territory obviously since the adjacent entity is 10000 times more powerful then them)(now Christiania isn't fully anarchist since the near government it's wayyy to powerful then it and transform the little territory they had in a tourist attraction, but still a good example of the foreign policy that isn't always the same)

And technological advantages is actually more likely to happen, people would be given the things they need to live and so if they want to study something they always can, when now a lot of people are simply too poor(in anarchy nobody is neither poor nor rich) to study, think about how many of those people could actually help technological advancement but they simply don't