In my experience, green coris' can live with other wrasses, but generally of other types- like the fairy wrasses. However, anytime I tried introducing another Halichoeres, it ended poorly. My green coris was a very high-strung fish until I added a yellow tang which promptly let the coris know he was the new king. You will not be able to keep a cleanup crew with a green coris either, they are just a fancy snack for them. Shrimp too.