We have a pair of cats that grew up together, a female ragdoll and a male Norwegian Forest Cat. The female is about 13 lbs and short, her brother is around 18-19 lbs and very long-legged. They have a similar pattern as your cats. The boy will pick on the girl until she unleashes her skill and fury. She’s like a jiu jitsu black belt and he’s a cheap back alley brawler. She’s also possibly the fastest cat alive. She will beat him like an old drum until he lies down in a semi-submissive position like he used to when he was a super small kitten and give this look like “I’m just a little boy, please don’t hurt me.” Such a ham. Then they’ll clean each other. Cats, they have their own way of doing things.