If he was even half as good as you think he would have walked into the PL and torn it up, he hasn't and doesn't look likely too anytime soon, but he has undoubtedly improved the team.
But he doesnt have a cat in hells chance of reaching Modric's level, there's just a huge gulf in ability let alone footballing intelligence. After Xavi Modric is the best central midfield player of a generation. That said its not a fair stick to hit other players with.
As for Dele, rumour is PSG are going to table a £50m bid, if we took it and he went then by 23 he will also have plenty of titles and awards to his name, but it won't improve his level.