Germany!? A flawed film.

It seemed to me that the film was set in Greece, especially since the language spoken is Greek. To have arrived in Germany the children would have first had to have crossed what was then Yugoslavia and next Austria, yet the first border crossing they come to needing passports is...Germany! If they had crossed road borders undetected up until Germany, why didn't they have any language difficulties and why was the young Greek man about to start military service (so still in Greece, presumably) with them until the near end? If the last train was a trans-European train why did they ask only for a ticket to 'the border' and why didn't they face any passport checks before Germany?

Am I missing something? Or does this make no geographical sense? It's a needless flaw. Why Germany!?