HELP! My rat is turning into Mike Tyson

[Desert Arabian]

My rat Peanut is constantly beating up my somewhat new little guys, Fred(r) and Oscar(l) . She often corners them and does a "stand-off". They stand on their hind legs with their mouths open, bobbing and weaving, then finally one lunges forward and attacks the other rat. Fred and Oscar are afraid of her when she does this (obviously), and whine/wimper like a dog. But when she's nice to them, they sleep together. / I have no clue why she does this. Territorial? I'm thinking maybe she is the alpha-rat?! For the most part, I let them duke it out, unless she is getting really nasty. Now, it is getting way out of control, Peanut is ripping out little chunks of fur, and now she has become Mike Tyson, she ripped Fred's ear today. I cleaned it with warm water FYI.
I don't think it has to do with the introduction process, from when I got Fred and Oscar, it spanned out for more than 6 weeks, and I introduced them slowly. I am clueless, and I have done a little bit of research on it, but come up empty handed. Can anyone lend me a little bit of advice?? Thanks!!


P.S. Sorry about any spelling mistakes, just a little tired.