I have both of those in my 75g, but they are each paired with separate pistols and have made their homes on opposite ends of the tank. The YWG was added second and before he paired up with his pistol he would wander the tank, I never saw aggression from the Randall's but he would chase the YWG away if he got really close to his den. When I say close, he would have to get within a few inches before he cared.