Why complicate things so much if you can just go along natural borders such as the Alps and the Baltic-Adriatic pass:
https://www.theapricity.com/forum/sh...mp-East-Europe
South-Eastern Europe:
Austria, Hungary, Slovenia, former Yugoslavia, Romania, Bulgaria, Greece, Albania, South Italy.
South-Western Europe:
North and Central Italy, Switzerland, South France, Spain, Portugal, Sardinia, Corsica, Baleares.
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With the rest being North-Western Europe, North-Eastern Europe, Scandinavia, European Russia.