Greek Macedonia is a region where significant numbers of Slavs had settled. It also today has much larger population than West FYROM. And I know about two studies which report higher R1a than I2a-Din percentage there (one study says 2 times higher).
Also Bulgaria for example is a Slavic country which does not have 2:1 ratio you wrote about.
So, I would say there was no strict ratio between I2a-Din and R1a among Slavs. But as it is obvious I2a-Din was in general more frequent than R1a among South Slavs.
Semi correct.
Greek Makedonia has a 23% R1a much of it fits with Eastern R1a the one you call Slav,
But Greek Makedonia has also significant diversity of R1a, which can be consider either as sink, either as homeland of R1a.
the R1a of Greece follows a downstream to Greece the one we known from history as the Dorian way. stops at 13% at Locri and follows a 5-8% to all Dorian lands, except Epizzephyreian Locri which is above 10%,
that road which is certified historically and genetically show the origin and genetics of Dorian descent,
in whole Italy (Magna Grecia) the biggest R1a concentrations are there where Dorians settled.
so the myth of R1a as Slavic mark is just a fairy tale,
in fact the I2a Din which has 2 major concentrations in Dinaric Alps and Skopje is better mark than R1a which expand even to Magna Grecia, a land which Slavs never settled to have such concentrations.
it seems like Slavs stop at Makedonia, and only families and followers via marriages with Palaiologos family went more south to Helmos mountains Peloponese,