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.
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.