I read an interesting article about the trends of successful franchise strategies. One that stuck out was to focus on a specific niche or positon on the field and have great play at that position and have that be your identity. For example, the Giants have always had great d-line play and the Eagles have usually had good secondaries. I believe the Saints are doing this with running backs.
Don't get me wrong, Brees is the player on offense that runs the show, and everything resolves around him. But with that, the Saints run does not really need a number wide receiver. The current #1 receiver, Colston, is a 7th round former College TE.
The rb position is the area where they can distinguish themselves. They have had an outstanding prospect at rb since Payton has got here. This year they brought in Ingram and now Darren Sproles, to combine with Pierre Thomas and Ivory. I think they team is going to keep adding rb's year after year regardless of who is on the rostor so this position becomes synonymous with being a strength of the team.