I've been digging pretty deep, but it would take too long to explain everything.
I'm just going to concentrate on a few things first.
1. The Saints traded for Roby because he can play both outside and in the slot.
2. They have Lattimore on one side with a rookie on the other side.
3. Their main slot guy is Desmond Trufant, who's getting up there and had a bad year last year. (Why he was cut by the Bears).
They Saints also have PJ Williams as the back up CB.
4. The rookie showed well in the first game against the Packers.
5. Lattimore missed the second game.
The Saints were still easing Roby in since he doesn't know the playbook and all that.
They played the rookie a lot, with Roby, Trufant, and PJ splitting the rest of the snaps.
Display Snap Counts by Team
www.footballguys.com
The rookie was targeted a lot, but according to a Saints fan website, he didn't look really bad.
(I guess the rookie has some fans.)
6. In the third game, Lattimore returned. He and the rookie were given the snaps at CB.
The Saints have 3 pretty good safeties (M. Williams, Jenkins and Gardner-Johnson).
The opponent played more TEs, RBs, and FBs so the Saints played mostly with 3 safeties in this game.
7. In the fourth game, the Saints also played a lot of 3-safety set if you look at the snap count from the link above.
Notice how Lattimore and the rookie still got all the snaps at CB, with Roby playing 32% (most likely as a slot CB); the other two DBs had just 1 snap.
Both the rookie and Lattimore actually gave up a lot of catches, if you look at the Advanced Defense Stat on ProFootball Reference.
But Lattimore just got a big extension.
Payton somehow stayed with the rookie, despite calls to bench him.
NFL and PFF player stats for New York Giants CB Paulson Adebo on Pro Football Focus.
www.pff.com
The New Orleans Saints just took an embarrassing loss to the New York Giants. Paulson Adebo was a big reason as to why that happened.
whodatdish.com
(read the note of the uploader).
There's another YouTube video that was more specific on that, but I can't relocate it at the moment.
At any rate, a lot of fans are now thinking that Payton need to bring Roby in and bench the rookie.