Leghorns can be a little bit pecky. I had Calfiornia Whites at one time and they are a Leghorn cross. I have a Brown Leghorn now who is still a pullet so we'll see. But I did get rid of my Cali. Whites because of their pecking. I think I had a Leghorn or two in the mix too...don't remember.
But if you are not seeing blood drawn and no injuries, I would definitely leave the flock together. More work caring for two flocks and also, if no injuries, then no problem.
Do make sure you have two feeders though, as the EEs especially may be timid and not eat enough if they are being bullied. I have seen EEs bullied before.
