The article you posted actually proves that quoting: According to eastern homeland theory, prior to becoming known to the Roman world, Slavic speaking tribes were part of the many multi-ethnic confederacies of Eurasia - such as the Sarmatian, Hun and Gothic empires
All Slavs share a common heritage.
According to the authors most Slavic populations have similar Y chromosome pools - R1a. They speculate that this similarity can be traced to an origin in the middle Dnieper basin of Ukraine during the Late Glacial Maximum 15 kya.[29]
Another quote.
Stop humiliating yourself posting articles that prove my point:)
They're shared as much as Anglo-Dutch affinities are.
Quite a bit more i'm afraid :) Linguistic similarities, cuisine, music, there's much much more in common between say Poles, Slovaks and Russians then between French, British and Dutch.