I don't know much about kole tangs, but in my 120 I have 3 tangs: purple, blue hippo, and sailfin. They don't fight, even though sometimes they swim into each other. The sailfin and my foxface always hang out together, whereas the blue and purple are each loners, more or less.
When I put nori on the veggie clip, they take turns eating at it. Sailfin gets in first, blue hippo sneaks in bites between the sailfin's, while the purple just simply gets the leftovers.