Well it's just plain unfair to compare German efficiency and thoroughness with... anywhere else in the world.
I wouldn't recommend calling them German. :)
'The official language of Zürich is (the Swiss variety of Standard) German...' [1]
Northern Switzerland was founded by Germanic tribes, after all.
[1] https://en.wikipedia.org/wiki/Z%C3%BCrich
[2] https://en.wikipedia.org/wiki/Languages_of_Switzerland#Germa...
The term is not restricted to only refer to modern Germany (which didn't even exist as a unified state until the late 19th century).