why do you think Vojvodina Serbs should be the most Slavic genetically? Historically, Vojvodina Serbs are a just a mix of Serbs which settled here from all other regions further south. They should represent the average Serb genetically. There are 20 other ethnic groups in Vojvodina, but afaik Serbs mixed the most with Banat Romanians, which would just pull them south. All the other ethnic groups in Vojvodina are catholic and protestant which was a big barrier for intermarrying.
the sample of 43 Lika Serbs i have ranges from 24% - 34% Baltic,
average 29. i expect Vojvodina Serbs to have a similar range to this.
based on some individual Serb results from
Banija and
Mačva, i expect on a larger sample the individual range here will probably be 26-36, and the
average 30. These should be the most north shifted Serb regions, not Vojvodina.
on My Montenegrin sample, mostly from Podgorica, which is the southern part of the country, the range is 21-29,
average 25.
based on some individual results i think the Serbs from regions like
https://en.wikipedia.org/wiki/Prizren and
https://en.wikipedia.org/wiki/Vranje will also have such a range and average.
all other Serbs should be in between.