Smalling is your typical average English player. He's a mid table player. Rojo has got something special about him. He's a bit like David Luiz in a sense, you either love him or hate him. But the fact is, these types of defenders are always more successful than the likes of Smalling and Jones and Shawcross and the like. The media hypes these guys up as "REAL proper defenders" but the truth is, they never accomplish anything. The best teams in the world always have a defender who takes risks, passes it out from the back and isn't afraid to try something. The media paint these guys as donkeys but its funny cause their accomplishments speak for themselves. Real have Ramos, Barca have Pique and PSG have Luiz. You ask a Paul Merson or a Jamie Redknapp and he will try and convince HIMSELF that somebody like Gary Cahill could do a better job.
Rojo has starred in 3 finals for Argentina in the past 2 years including a World Cup where he managed to get into the Team of the Tournament. Smalling will never ever accomplish that. He's not talented enough.