again, it's hard to say for sure. you'll just have to try and see what happens. i never liked the yellow tangs much so never kept one, except for in the gym tank. it wasn't aggressive towards anything. i have found hippo tangs to be the most peaceful of the tangs. everyone i have ever kept or seen has shown zero aggression. never kept a kole tang long enough to observe aggression, and lastly, of the tomini tangs i have seen, none appeared dominant enough to worry. all powder blue tangs i have kept/seen were mean and nasty towards any other fish in the tank. sailfins seem pretty cool. the desjardini in the gym tank showed some aggression towards the copperband butterfly, but it didn't last very long.