Hi BFG, yes, i understand the growth part. Based on my observation, yellow wrasse is definitely more peaceful species of the two. However, my green wrasse has not really been aggressive. In fact I recently added 2 small yellow wrasses in the MT and the green wrasse don't really bother them after the initiate period of maybe 1-2 days. Likewise, I believe we introduce a rhomboid a while back it also never really bother.
However, I have to say, different people have different experience and luck so it may all come down to that as well.. Just like we can never keep PBT. haiz.