回复：通过LC办绿卡-招聘广告上,对中文的要求

In my case, the attorney added chinese required in job post becuase my job required regulary contact with China. I asked my attorney the same question as you did, the answer was it's OK to have language requirement but you must justify it. I am still waiting for further result, so can't share with you if language requirement works better nor not. But I think in your case, my suggestion is not to add language. Your primary job is not to help communication using Chinese in the company. So it doesn't matter and will raise the red flag to Labor dept.