Cirrus is asserting his dominance. He may or may not succeed, but it is up to the cats to figure it out. As far as us humans go, it is none of our business. The only time I intervene is if I REALLY think one cat is getting the short end of the stick. (In my house, that example would be when Sterling fights with Fern....there is NO reason for that as she always minds her own business). So let them be, do not worry, they will work it out.