We are focussing on reality. You forgot, or didn't know, that Ibrahimovic was amazing in his last season for Inter Milan. The price wouldn't have been as high had he not had performed the way he did. But because of the price, the expectations were very high. He was definitely a flop and not because of his figures, but because he had one season and then was sold to AC Milan afterwards. At Manchester United, his numbers register well, but Barcelona have a different philosophy and I feel you're ignoring the price tag, for the sake of enhancing your argument.
The thing is, Ibrahimovic has known to get better as he plays more with the club he's with. When he joined Inter Milan, he only scored 15 league goals. In his final season, he scored 27 league goals. When he joined AC Milan, he only scored 14 league goals. In his final season, he scored an impressive 28 league goals. It's been that way for the most of his career, with a couple of exceptions (Juventus, for example).
I do understand your point, but blaming this all on Ibrahimovic is a bit ignorant IMO and the Sanchez comparison is a poor one. The reason I say this is because Sanchez operates as a winger, a false winger to be more specific, so he has to press more and work harder defensively to cover Alves. That's not to say that you're wrong because Guardiola took a good move in taming Ibrahimovic's ego, but with an open mind I'd like to believe there's truth in the way Guardiola managed him. Some of them are not fabrications. And the use of the swear words in Ibrahimovic's book show how strongly he felt.