That could work, but it's not perfect. I think part of it is that it's all very contextual - for example, if there is an English language version of the exact same content, then I almost always want the English language version, even if I'm searching within Germany, plus there's a bunch of exceptions where e.g. I always want German Amazon (because that's where my account lives).

Google mostly gets this right, at least in my experience, although it's become a lot worse recently. Having to configure it with bangs might work, I'll have another go at that in the future.