>I don't think skillfully translating into idiomatic, grammatical, well written text is meaningfully easier then composing the text yourself in the first place.

You don't think so based on what? One does not have to be a subject matter expert to translate from one language to another.

People that know more than one language are translating all the time, both consciously and unconsciously (While they're proficient in language A, they may "think" in language B). It's not as much effort as you think.