In mid-December 1919, the German troops were evacuated to East Prussia and Schimana was released from service on 20 April 1920 as a Leutnant of reserves.

Schimana joined the Nazi Party (NSDAP) on 7 December 1926 (membership number 49,042) in Munich.

[2] At the outbreak of the war in Europe, Schimana took over command of a Feldgendarmerie battalion in Poland, France then the General Government up to 1940.

[1] On 4 September 1941, Schimana was appointed SS and Police Leader (SSPF) for the Saratov area, and later attached to the staff of the Higher SS and Police Leader (HSSPF) for Central Russia until July 1942, taking part in rear-security operations.

Reporting to Friedrich Jeckeln, he was responsible for the formation of the Schutzmannschaft (collaborationist police) battalions.

[2] On 18 October, Schimana was appointed HSSPF for Greece, in place of Jürgen Stroop, a position he held until the withdrawal of German forces from the country in September–October 1944.

After the German withdrawal, in October 1944 he was appointed HSSPF of the SS-Oberabschnitt Donau (Main District Danube), which had its headquarters in Vienna.