Could you kindly explain to me why when Serbs where in troubled times they migrated to Austria and not Tzarist Empire or to Poland?
https://en.wikipedia.org/wiki/Migration_of_the_Serbs#Great_Serb_Migration_(1690–91)
Please take into account that Poland was quite ok in those times, even some Scotts migrated to Poland.
Is not normal to integrate easier with people of larger Slavic ethnicity if you are a Slav?
So at the question "Are South Slavs more Balkan Native than Slavic", it depends at what we are referring.
If we are talking about the genetics and we call Slavs those people that migrated around 600 AD, is different from ethnic group to ethnic group and from person to person.
If we are talking about ethnic groups, is again different.
Bulgarians rather seems more Slavic as ethnicity, than Balkanic, while Macedonian look rather more Balkanic as ethnicity.
Montenegrins are between Slavs and Balkanics.
But as we move to Serbia, Serbia are more West Germanic like,more Austrian as ethnicity, to be precise and is same with Croatia and Slovenia.
From what I hear from other Slavs, Serbs are even more close to Germans as way of being, than Austrians are close to Germans.
For Bosnia, I do not have an opinion.