I don't know what game you are playing. DeCODEme only has 9 European populations from 6 countries in its
Genetic Atlas : Iceland, Orkney, France, Basque, Italy (unspecified Italian, Tuscan and Sardinian), and Russia (Russian and Adygey). The exact same population are used in their
Map of kinship.
So I am not sure where you found your "many public samples from all over Europe". Don't you mean one-to-one comparisons with other customers in the Your Friends section ? That's also possible at 23andMe.
There are 3 main reasons why such comparisons are unreliable :
1)
Single individual matches are unrepresentative of a whole country. You will sometimes find good matches in one country, but others that are only distant matches. If your 3 best and 3 worst matches are from the same country they even each other out. There is no option at present to make averages for all members from a selected country. The problem has a solution; it's just not available to us yet.
2)
One's best matches vary according to the resolution chosen (fragment size). One's matches at 1Mb aren't the same as at 250Kb or 5Mb. Depending the what you choose your top matches will be in different countries. Some of my best matches at 250Kb (64%) share 0% at 5MB. One person who shares 0.5% at 5MB has only 62.6% at 250Kb. There are so many resolution levels that no consistent ranking can be made. In other words nobody fits neatly into one region.
3)
Interpersonal differences within Europe aren't significant. You are unlikely to find any match at 10Mb or 20Mb unless you are related within a few generations. At 5Mb pretty much everyone shares between 0% and 0.5%. At 1Mb it varies between 18% and 20.5%. At 250Kb it ranges from 62.5 to 64%. Differences are tiny and random. What's the significance of 0.1% more or less in common with someone ?