You could try picking up one of the BR's and plopping them down in with the littler ones. Sometimes just splitting them from their buddy and taking them out of their spot is enough to calm down the pecking. Maybe put a treat in at the same time, something scattered across the brooder.
BR are one of my favorite breeds, they have so much personality. Just be sure to handle them a lot as chicks, they go through a really skittish phase and then come around into confident, curious, and sweet chickens.
BR are one of my favorite breeds, they have so much personality. Just be sure to handle them a lot as chicks, they go through a really skittish phase and then come around into confident, curious, and sweet chickens.