Yes, they've got to be Poles. But look at the car, that's a WW1 or 1920s type car. Think Ford Model T as opposed to an old Willis or Olds from the 1940s.
A long time ago, someone posted here that there was a Surinamese man who was in the Netherlands when Nazi Germany invaded and apparently spied for the Gestapo. I felt then that he would have been coerced. One thing the Jews and the Gypsies and Communists and Catholics and Poles and Slavs and Jehovah's Witnesses and democrats and others who were sent to Nazi concentration and death camps don't like to talk about are the people who took security jobs and jobs with responsibilty. there were literally Jewish overseers in those camps.
If you were a young man, and you wanted your family to survive, one might take a job forcing people to work.
Personally I think those photos are photoshopped. Poland didn't have colonies in Africa - unlike Britain, France, Spain, Portugal, Netherlands, Belgium, Italy (Lybia and Somalia) and Germany (parts of Uganda and Tanzania and what is now Namibia). I find it hard to believe that an African would have been on a military mission to Poland in the 1920s - he would have hadto have had permission from his colonial power.
Check out
http://www.amazon.com/dp/0060959614/?tag=vp314-20
which is about Hans Massaquoi a man who was born to a Liberian ambassador and a German woman. There's even a pic of him in Hitler Youth uniform at age 6. Needless to say his mom was horrified. He remembers being told by a Brown Shirt "after we finish off the Jews we're coming for you". He survived the war and eventually joined the US Army and then went to work for Ebony. Hans Massaquoi is a great black journalist and photojournalist.