If they would play in the same league, maybe. Tevez spend his time in England playing alongside Ronaldo, Rooney, Nani, Aguero, Silva etc. Del Piero wasted some seasons on Iaquinta, Amauri, Palladino etc. Also there are a lot more scoring opportunities in England due to the attacking style, just look at league goals f.ex. 07/08-11/12 Juve scored 321 league goals and 07/08-08/09 United + 09/10-11/12 City 374.