It's a little strange that this particular scene was shown in the movie (unless they simply hired 2 extras who happened to speak the language). While is is certainly possible that some people of Czech origin ended up fighting in Wehrmacht, I think the numbers were quite small. I am no historian, but as far as I understand:Somewhat tangential and not fit for this thread...but, the two German soldiers that try to surrender and beg for their lives at the beginning of Saving Private were conscripted Czech soldiers pleading in Czech. That got by me for over 20 years. The Americans quickly wasted them.
"real" Czechs who lived in the occupied Protectorate Bohemia-Moravia were not eligible to get drafted because they were not German citizen, so the only ways how a Czech would end up in the German Army were:
- if, following the split of Austro-Hungarian Empire in 1918, the Czech stayed in Austria (which was later annexed by Germany and all its citizen turned into "Germans"). That is certainly a possibility, because e.g. a lot of Czechs used to live in Vienna before 1918, though I think that between 1918-1938 quite a lot of people left poor post-war Austria to return to the much richer Czechoslovakia
- or, if the Czech stayed in the annexed Sudetenland in 1938 (as all citizen of Sudetenland were also immediately turned into Germans without exception). AFAIK, vast majority of Czechs left their homes after Sudetenland was annexed and moved inland into Bohemia and Moravia, so pretty much the only people staying were partners in mixed marriages. Again, I am not a historian, but I don't think many people fell into this category, as Czechs and Germans were quite segregated in those times. (I was born in in one of the "iconic" small Czech towns - with nearly 100% Czech population - but grew up something like 12 miles away in a town that - before all Germans were expelled in 1945 - was nearly 100% German. Interestingly, 1945 population of that town was 30K+, while the present population is about 20K...)
- or, if the Czech inside the Protectorate Bohemia-Moravia suddenly remembered that he actually has German ancestors, and applied for German citizenship...