Creoda added Dutch regional averages iirc based on fully Dutch kits with family trees he collected, you can trust his work.
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By the way, with which company did you test? I noticed new versions of Myheritage and 23andme have eastern pull due to lower snp count.
I think some were added before, like Belgian never existed in K13/K15 and replaced S.Dutch for some reasons. Except no Belgians cluster here if you look at our pca's (because it's indeed S.Dutch). Provence is completely wrong, nobody cluster there either (it's right next to Veneto and Lombardy)
Im sure the new ones are more serious and legit averages if Creoda made them altough the difference between central and north dutch seems anecdotical, like two siblings or neighbours, but why not. What im not sure about are the old ones where somebody renamed/swapped academic samples.
No, the Dutch samples are academic, Piotr uploaded them. And they are quite fishy, some were like 2-3% SSA and/or East Asian. For Dodecad I had to eliminate nearly half of them for said reasons. So D K12b doesn't have Dutch_North and South, only one Dutch average.