Doesn't fit the narrative.
Fernandinho also made an immediate, and probably title-winning, impact by going stright inot the the team and covering so much ground and doing so much defensive work that Yaya was free to go forwards and score 20 league goals.
So really, we've got
Aguero 2011
Fernandinho 2013
KDB 2015
All who made immediate impacts for the club.
And this season we've signed Gundogan, possibly the best midfielder in the bundesliga last season, who apparently won't make an immediate impact because he's missing the first 2 games.
Then there's Sané who will probably go straight into the team and massively upgrade RW, and possibly even Stones as well.