Mean Feral Chasing Away Others

I have been feeding a few ferals in my neighborhood and one mean tomcat has been coming around and chasing the others away. He has permanently chased two away. I feel so bad for them. What can I do? None of the shelters near me have room. I have tried feeding the mean one away from the others but he still chases them. He even chases fixed ones so I'm not sure if it's for domination.