I have 2 blue flasher wrasse, not sure which one is male. One is smaller than the other. I have also a Mccosker flasher, and (Had) a Carpenter flasher in my 205. The larger of the blue flasher would fight with the Carpenter, until one day it managed to jump to its death. I have netting on the tank, but it made it out as it was still rather small. The flasher that I have in there now all seem to be fine and not fighting at all. The blue flasher is the largest, followed by the other blue flasher and Mccosker. If you have a secure enough lid, and big enough tank I would say more than one male is fine. They fight on occasion, but rarely do you see them chasing each other around the tank all the time.