I have a Carpenter's Flasher Wrasse (male initial) and a Sixline together. They do just fine. The 6-line, if anything, is the weakest fish in the tank and most skiddish. My yellow watchman goby is the boss of the tank for sure. If either of the other fish approach the bottom of the tank he opens his mouth super wide and chases them the hell out of there. It's comical.
The flasher and sixline swim together, though...and seem to like each other just fine. They eat together as well but the flasher is definitely higher in the pecking order.
I have been considering adding an ORA Maroon goldstripe or goldflake maroon, too as the final fish....but I haven't decided yes or no yet.