I am not sure about counties, but I am descended from Betty Buelow, who was the daughter of Ernst Buelow (b. 1827/30 in Mecklenburg, Germany). Ernst married Dorothea Karburg, (b. 1837, also Mecklenburg) and had Louise, (b. 1863) Clara (b. 1871), Bertha (b. 1878) and Betty (b. 1878)
However, there is also an Ernst Buelow, born same time/place who married Ana Margarete von Zaplin, also from Mecklenburg. I have not been able to determine if these are the same individual.