Let's break this down, via wikipedia:
Originally posted by tetrahedron
All three are historically Christian,
The Netherlands is one of the most secular countries in Western Europe, with only 39% of the population being religiously affiliated.
Most Finns are members of the Evangelical Lutheran Church of Finland (79.7%).
80.9% of the population of Denmark are members of the Lutheran state church.
Two out of three ain't bad for your first assumption.
2/3 are racially heterogeneous (white) and the 3rd is majority white;
Denmark, Finland, or the Netherlands don't list race.
all 3 have populations < 10 million.
Denmark and Finland have about 5.5 million but the Netherlands has about 16.6 million. Once again, two out of three.
They are all European
Someone passed geography class.
and have cold climates.
Average temp. for each:
Finland: 7.5C in the south and 0C in the North
Denmark: 0C in the winter and 15.7C average in the summer.
So let's look at your assumptions for the optimum setting of a socialist state: Cold, European, small, white and Christian.