"...and especially with August Sander who might be the best portraitist ever!"
...but keep in mind that Sander was really doing typology, not portraiture. It's an entirely different concept. Portraiture tells you something about an individual, and is rarely documentary. Typology tells you something about a class or group in society, and is almost always documentary in nature. The fact that he was doing typology across all aspects of German society is what got him in trouble. He was documenting groups in society that many viewed as shameful, and documenting them in the *same exact way* he was documenting the upper classes, not placing any one group above or below any other. If he had just been taking people's personal portraits, nobody would have cared.