Shevchenko is the second best in the division and probably beats Nunes over five rounds [Due to Nunes gastank]. Shevchenko would murk Ronda.
People get blinded by the fact that Ronda was beating people in ten seconds, but what they are missing is that her game was built on a deck of cards. She bull rushes forward, gets the clinch, and tosses her opponents. That is all she has. There is no plan B. In men's MMA that gets you finished every single time. Even if you're Satoshi Ishii...
It worked for a while because WMMA is seriously shallow. Thing is, even if you are the worlds greatest judoka, it becomes almost impossible to do what Ronda does, once the competition gets past UFC one level... And once that happens, Ronda really has no place in the octagon until she develops a larger skill set, and that takes years.