Firstly, what are "these circular sentences' referring to? You have to read the text that comes before in order to understand this.
Anyway, this is how I understand it.
In Chinese the relationship of clauses and sentences is sometimes given by their order, and there is no specific word indicating the relationship. So if someone is translating it quickly, or doing a draft, he is probably using machine translation, then has to fill in a conjunction.
In my opinion, I don't think this is a problem of the language. I think the problem lies in the fact that the translators aren't very good.