You don't have to have pace to be a great Premiership player. Neither does pace make a player. Lack of pace is not any of those three players' problems. Neither of the three are slow, they're just not Walker-fast. Majority of players aren't. If Lamela's pace is what prevents him from getting away from players, how come Modric and even Van der Vaart used to skip past players? They're hardly lightning. It's the intelligence and knowledge and confidence that is alluding him at the moment. It's the knowledge that when he beats his man in Serie A he will have loads of time as that's how its played over there, but in the Premiership you beat your man and release quickly or go down for the free-kick, as you don't have time to beat the 2nd man or look fancy. Honestly I think with Lamela it could (and I mean could, with the right coaching, not will come) come because the tools are there. I think he's a lot more physical than people give him credit for and his skill is obvious. For me its just getting used to what is going on around him and how to play in the Premiership.
Paulinho and Soldado just aren't suited IMO.