Seems pretty straightforward, actually:
"We need to cast someone to play a Nazi for this episode."
"Remember that one guy we cast in Voyager? He was pretty good. Let's just get him back."
Both series had the same primary casting directors:
https://m.imdb.com/title/tt0244365/fullcredits/casting_director?ref_=m_ttfc_8
https://m.imdb.com/title/tt0112178/fullcredits/casting_director?ref_=m_ttfc_8You and your blasted Vulcan logic!
Way to dig for the heart of the matter. You've restored my faith in the process.
On the other hand, there have been actors that play Nazis all the time.
https://gamerant.com/the-truth-about-hollywoods-favorite-nazi/
To be specific, Kretschmann has played a Nazi solider in: Stalingrad (1993), Krigerens Hjerte (1994), U-571 (2000), The Pianist (2002), In Enemy Hands (2004), Downfall - Der Untergang (2004), Head in the Clouds (2004), Eichmann (2007), Operation Valkyrie (2008), Laconia (2011), Stalingrad (2013 - yes, a second movie called Stalingrad), Captain America: Winter Soldier (2014) and Avengers: Age of Ultron (2015)…. And that’s just the times he was a literal Nazi, and not a vaguely fascist German character.
To be fair, if you're a character actor in Hollywood, can you really afford to be turning down parts merely because they're typecasting you?
As long as people are making media with Nazis in it, someone's gonna get cast to play the Nazi. Might as well cast someone who understands the role.
It doesn't mean they believe in it, which is discussed in the very article you linked.
Missed conspiracy and enemy at the gates, shame
Max von Sydow played a Holocaust survivor in several films. He was Swedish. Don't ask me to explain that.
It's them cheekbones
He's got the German last name and everything.
"Central Casting? Yeah, we need a Nazi, who do you have?"
"We have Leonard Nimoy, William Shatner, and DeForest Kelly?"
