Sterling hasn't shown anything to suggest he will be a world beater. Hes English and overhyped, KDB has had one good season in Germany. Theres a reason why Mourinho let him go. Pedro is a better player than both of these, Silva is probably better than Mata but if Mata is played behind Rooney in his best position then he isn't far from Silva. Aguero is a lot better than Rooney but to say theres a huge gap is just plain rude.
Pedro isn't as good as de Bruyne, let alone be better than him. Pedro will be a very good fit in our current setup but let's not pretend he's something he's not.