None of this makes what you did a good trade. Whether or not Rivers produces more FFB points than Brees is immaterial, because you drafted Brees ahead of Rivers, meaning you could have had the guy you wanted plus any one of these 16 players drafted in between:
Randy Moss, Reggie Wayne, Miles Austin, DeAngelo Williams, Calvin Johnson, Steven Jackson, Ryan Grant, Brandon Marshall, Larry Fitzgerald, Tony Romo, Roddy White, Pierre Thomas, Cedric Benson, Desean Jackson, Matt Shaub, Jahvid Best.
Several of those players make you instantly better. You can't tell me you wouldn't want one of them, and you left that on the table, which makes it a foolish trade. If you were so certain that Rivers would be better, you would have picked up one of them and drafted him later. Besides, the upgrade from Rivers to Brees right now is 16 points, 3.3 points a week. Your success is more likely due to the ridiculous numbers from your TE's.