I have two male Lubbock in my 320 and they do fine with each other for months now. Both grew well and are fat. They do flare at each other more often than at other wrasse. There are about 20+ wrasses in this tank.
According to evolved, Pintail Fairy are more docile,. I would presume that you can keep more than one if the tank is big enough. The question is how big is big enough? 320 gal or about 1200 litters may be big enough for Lubbock wrasse.
BTW, I DON'T HAVE A PINTAIL. Mine did not live past QT. I am looking for another one.