Oscar was stiffer, less fluid, and less athletic than Leonard, AND he didn't handle southpaws well. So although he beats Kalule, he doesn't do so as easily as Ray did. Leonard really fucked up Ayub cause of all the various angles he was hitting him from. Oscar didn't have that type of talent....he was more basic. He still beats Kalule handily though, but Kalule would definitely win some rounds.
That's very possible. Oscar wins, but people thinking this is a wipe out are just trying to believe Oscar could duplicate Ray's performance, when his track record against southpaws shows us he wouldn't. "Like I said before" Leonard was just a lot more athletic and dynamic than Oscar and was nailing Kalule from so many angles that Kalule just looked plodding. Oscar's more of a straight line and side-to-side fighter, Kalule would have more success against him.