I have 3 albinos, 2 panda, 2 delphax, 2 julli, 5 sterbai. The albinos hang around on their own, they dont pay much attention to the others as do the pandas who seem happy on their own. The others sterbai, julli, delphax do stay together.
Since they are social fish, corys love to be in large groups. When there are more than one species in the tank, they'll spend at least some of their time together and part of their time with their own. Corys never make it a habit to ignore each other in a tank.