I think you have confused Dzeko or Bony or maybe Zlatan with Aguero. One of Aguero's strengths is his mobility and agility.The crux of the matter for all Kuns brilliance he doesn't work hard enough, when he first arrived he worked his bollocks off, within every year it gets less and less, that's why he won't ever reach his full potential, Pep won't let him stroll about, why should he?
I do think his game has dipped a little. He's not as quick as the player who arrived from Atletico, but he's still a fantastic striker.
We got in some great opportunities against Everton, and Barca, but scored once. I am sure we would have done better against Everton had he been fit. The tactics were spot on against Barca. We had the upper hand as a team before individual errors blew it up in our face, although I think we massively overdo the passing with Bravo especially against a team who press. Too risky.