Robinson Cano is a 2B with some flexibility to move to another position (3B, LF, RF & 1B are not out of the question). Prince Fielder is stuck at 1B until his knees, feet or back gives out and will only be able to DH. Also, the level of difference between what the Cubs currently have at 2B and Robinson Cano is vastly greater than the difference between Rizzo and Fielder/Pujols. You are talking about a guy in Cano that could be a HOFer if he continues at his current pace versus a 1 dimensional guy in Barney. At least with Rizzo vs. Fielder Pujols, you are comparing a potential perennial All-Star to two likely HOFers.
First off, it was determined by management that they were going to go after Rizzo and not Fielder because that was there choice. I get that. But no one will ever convince me that they made any honest attempt to go after Fielder as you say they did. It generally gets to the media somehow who the serious bidders are, and a lot of times it is leaked at the amount too.
Also, to say that Cano to Barney is a massive upgrade, versus Fielder/Pujols to Rizzo holds no water. The Cubs had no first basemen, so anything over Carlos Pena would have been an upgrade.
Sorry, but at the time, a failed major leaguer in Rizzo was not an improvement over Pena.
As to the Cubs not being closer this year compared to the 2012 season, they are closer due to the added progression of their prospects (Soler, Watkins, Shoulders, Vogelbach, Rusin, Rosscup, Hendricks, Johnson and Baez to name a few) along with the added progression of the young players currently on the major league team (Castro, Rizzo, Samardzija, Russell, Wood & Castillo).
And they would have been just as close and might have made the playoffs if they actually fielded a quality team to go along with Castro, Rizzo, Shark, Russell, Wood, and Castillo at 1060 W. Addison. They had those players last year, and added E-Jax and Schierholz to compliment them.
Imagine the possibilities if they actually did both?