My thinking was that Rodrigo as LB was meant to exploit some perceived weakness in the opposing winger, but I have no idea if that is the case. I suppose it could also have just followed from the switch in our wingers. Who knows though.
Agreed that Zivkovic is kind of one dimensional. Moves like Mak but plays like old Stoch. Once he gets shut down, we are weaker (though as I think you once said, their efforts to shut him down should leave our other players more free to attack).