I've got one older bro, who's not entirely stable and firmly believes in might makes right, when it comes to a disagreement, and one younger bro, who's the absolute opposite of him.
This usually results in me having to be a passive mediator after calming both down with physical violence.
Or at least, that's what used to happen until my younger bro decided he wanted to take martial arts.
Now I simply watch him own our older brother when he tries something stupid, and shrug my shoulders apathetically.