On the general side: I'd say the German approach for kids (2-12) is "super strict on the basics, then have at it." So you are very strict that they must stand behind the yellow line, don't interrupt grown ups, behave yourself at the table, etc, but once you have the core down there are few restrictions (this changes as you grow up...I like to joke that Ordnung is the German state religion). So he was used to unsafe playgrounds, coming home late from just exploring the U-bahn with his friends (all ignoring texts from parents) etc. He compared that to American kids who seemed to always being told not to do things without having a set of basics to make their own decisions. He had one Palo Alto classmate who was grounded if he wasn't home 15 minutes after school let out!
An example: in grade six he and his friends found a bottle of vodka in the schoolyard (urban school). As any 12 year olds would, they took one of their gym sneakers, filled it with vodka, and set it on fire. The maths teacher passed by and said "boys, school starts in a few minutes; don't be late" and kept going. He told me he'd be expelled from his US school if he had matches or a lighter. In Germany that didn't even rate a letter home from the school.
He also complained that grownups were always involved. Schools have police officers in them, scouts have parents involved, etc. Kids don't get to run things and screw them up like they do in Germany. I went to a Christmas service in a church where the kids wrote and put on a Christmas play -- apparently Noah brought the animals, 2x2, to see the newborn. I am not christian but I'm pretty sure that isn't doctrine -- but everyone seemed to like it.
He found the US school routine quite rigid with little time for exploration of the material but instead memorization. If anything the US seemed more like the asian schooling my mother went through, or perhaps the prewar Prussian system. I know the US kindergarteners are told to learn the alphabet while the German one was mainly focused on getting along and learning, by the end of the year, to keep your clothes on all day. They left the alhpabet (in two languages!) to the first grade.
HTH