After having worked with people from former Eastern Bloc countries, I would nominate a few of them for direct communication, e.g., "I won't do that because it is a stupid idea," or, "Can we discuss this when you know what you're doing?"

Scandinavian are quite different between each others as well.

Scandinavian cultures are not uniform also. Danes can be very direct; Swedes - not so much.

The Dutch especially. It's refreshing

I'm Greek. I don't know about other Mediterranean cultures, but I assume they're similar.