I'm not sure even Ibra come back to San Siro will give any significant impact to AC Milan players, even many people say he will inspire young Ac Milan players, but it will not give any change to win a match if they doesn't have good strategy.
Maybe to raise the morale of the team and guide new players / young players owned by Milan Ibra can do it. However, to change the AC Milan game I think it will not happen in a short time like you said. They clearly need a fairly long process. Besides they also need to buy new players later and try to bring in a new coach in accordance with the club's own philosophy. If indeed Pioli failed to do his jobZlatan has only been in the AC Milan contract for only one season. If Ibra still cannot provide the best direction for Milan then I think this is said to be a failure, even though the guidance is still no change, I believe this needs a total change from player to coach if you want milan to remain Up.
I don't see him as a main stay for the Club nor even some kind of quick fix for the team. He is 38 years old and he only scored a lot of goals because he is just playing in the MLS (no offense) and the level of competition is considerably different in European leagues more specifically in Serie A. In my opinion Milan only did this as a sign of hope or something that fans would appreciate like what they did to Kaka when they brought him back and fans really love it. It won't really be different for Zlatan as fans really loved him during those time. He is just here to cheer the crowd and not win some games. Hopefully in the next transfer window AC Milan will make some actual changes where the team could be relevant again this season.
And you should also take note that Bernard Arnault, owner of Louis Vuitton, is trying to acquire Milan and he is really aiming to give a big investment for the team, this is what will actually make some changes for the team.
