I have 2 large breeds in with my silkies and they do fine. BUT they’ve been together since they hatched. I did add 3 other bantam pullets in after about 4 months and the one bullied the silkies so bad I had to move it to a different coop. She pulled big chunks of feathers out and the silkie was terrified of her. You could try to introduce some to your flock but I’d have a backup plan just incase things went sour.