Notably both of these countries are english majority. I went looking for german debate clubs and found that we have some, but also that they're relatively young (the national debating org in germany was formed only in 2001), and were mainly formed based on inspiration by the english language sphere.

I'm also curious what exactly you mean with civil discourse? I don't know which style you're referring to, but i've seen people who cared primarily about discourse being "polite", even if the most horrible ideas were being presented as valid.