There were plenty Czech soldiers who first went to Poland (many even flew there with Czechoslovak airplanes) in March 1934 when Germans took the rest of Czech Republic, expecting German assault on Poland. Poland didn’t like them and they were often interned in camps, because Poland of course didn’t want to pull the German leg. Especially considering that Poland invaded Czechoslovakia (border areas) together with German and Hungarian troops in 1938.
Then Poland got into war so those Czechs there got to shoot a bit on Germans, but Poland didn’t last long. So many again went either to Russia (only to get to internment camps) or through Romania to France. Then again France fell and they went either to Britain or to North Africa. Meanwhile shit stirred up in Russia so those there got out of camps and to fight.
Russia was pretty fucked up because large numbers were trained as paratroopers. When the line got to the eastern part of Czechoslovakia, the Ruskies sent those lightly armed soldiers directly against German lines instead of parashooting them behind the line.