My suggestion is to get rid of the Leghorns and get some docile breeds that are also excellent layers, such as Black Sex Links or Australorps. Your problems with your Leghorns is exactly the reason I quite raising Leghorns many years ago. Whatever you decide to do, good luck.
x2 I havent added any leghorns or Rhode Islands due to them being more aggressive in a mixed flock. My GL Wyandotte is my current pain in the butt LOL She chases my bantys around and now the broody hens and chicks. However, she is so quirky and fun I haven't rehomed her. She isn't overly aggressive towards them just likes to chase them away from her. Ont he other hand, My Blue Laced Wyandotte (from a breeder) just hatched some eggs for me and when the chicks were a couple weeks old, I was always holding them, cooing and talking to them. She started pecking at my leg and when I didnt get the message she jumped up on to my lap (another time on to my back) and snuggled in for some loving LOL It was the cutest thing-she needed a mommy break!