At first here are some genetic PCA-maps you give me. I have gathered some examples about individuals and ethnic groups to figure out the situation.
Here is how some Northern Europeans seem to locate on the maps:
Here are two mixed Finns, the first one has ancestry of 50% Finnish and 50% German, the second one is 50% Finnish and 50% Irish:
Here are two other mixed Finns, the first one is 75% Finnish and 25% French-Swedish, the second one is obviously partly English. I am not sure about the second admixture, but his name is English and his ancestral names are mostly English and Swedish, but also Finnish:
Everything looks fine on these maps. The Finns are the northernmost ethnic group and all those mixed Finns are closer the populations where they have got their admix from. But some things don't look as good as I expected after looking corresponding results at the Ancestry Composition.
Here are two results corresponding to the map 1:
And here are two results corresponding to the map 2:
It shouldn't be difficult to see the difference, mixed Finns on the first map are only half Finnish, and it is true. On the second map mixed Finns are fully Finnish. So what is the inside story? I can only make my conclusions based on the public information. I can assure, I have tried to find it out. But how hard I try I can't see any other difference than that two persons on the first map live in America and those two on the second map live in Finland. And they really live in these places. Can you explain it?