Now that you all mentioned it, I never really see any fights between my Orps. Any fisticuffs that get started always include the other breeds. And yes, without fail, when I see the start, it's because someone invaded the Orp's space, or that other bird just went after an Orp for some reason. A couple of them really know how to end a fight, but don't actively search any out. Bella could be trying to find her proper place in the pecking order. And hasn't because Mom keeps acting like a rooster and trying to break it up, then ends up fighting the other chicken. At least that's my take.
My long time #1 hen, Big Girl, was dethroned that exact way. Now, the pecking order is somewhat strange. Anyway, my dark cornish had a few chicks and didn't like one of the hens getting too close to them. Next thing I see, that DC is all over a hen and Big Girl rushes to break it up. Ended up getting her butt kicked by the dark cornish. But the DC doesn't really want to be "head hen." She doesn't pick fights. And neither does Big Girl. So Big Girl still sort of leads, but not. It's odd to see a bird (the DC) above the lead hen that is below some of the ones below the lead hen.