Why does Branagh possess a penchant for playing Nazis?

It is not obvious how the character portrayed Cruise in Valkyrie is a global hero. It is not obvious how it would have been in the entire world's best interest if Hitler was killed, but the Nazis remained in control of Europe. von Stauffenberg appears to be, at most, a German folk hero, playing the role of military victor Gen Lee to Hitler's incompetent political Jeff Davis. The Germans can scapegoat Hitler for losing the war & dream of an alternative history where the Normandy invasion is magically avoided leaving their Third Reich intact. In reality, the Allies were committed to total victory including a return to Germany's antebellum borders. This result required a Normandy invasion which necessitated the aerial bombing of Germany to acquire air supremacy. It appears extremely dubious that there were significant numbers of "nice Nazis" anywhere in Germany who were concerned with the well-being of the world.

On a tangent, people who point out fallacious goofs:

Both Colonel Claus von Stauffenberg and his wife Nina have very dark hair, yet all of his children have straw blond hair. This is genetically impossible.

should review basic chi square analysis for heterogeneous parents.