What's the size of the tank again? I'm definitely new to the wrasse family. My understanding is that most flashers are able to be kept together. My research says that you should keep the new one in an acclimation box for a couple days so they can see each other. Then after the lights go out release the new one so that there is no immediate aggression. You should expect some chasing the first few days but generally they should be fine. But definitely get other opinions. Like I said im new to the wrasse species. @Eagle_Steve can you also help?