I wanted to create a guide in hopes to help those who are looking for Redeemed. I believe some of the spots are set places, along with some random encounters around the map. They are usually found with the Zealot enemy type. I found Redeemed at the following locations
2 during the rescue mission for
during the Zealous Overreach in the cave
1 at Wayshrine of Devotion
2 at Wayshrine of Strength
1 at Tul' Shahk Monastery on the road to the top of the mountain
1 on the road between Wayshrine of Perseverance and the abandoned camp
The rest were random enemy encounters on the outskirts of the map i.e bone camps, outside caves etc...
Other potential spots:
During the final battle with the Zealots fighting, one could spawn there
Varuun camp or small hideout SE of the 2 large lakes, possible west of a crashed ship
Exploring moons of the gas giant in the same solar system
Sympathy for the Living sidequest
Refining Station south of Darza in the sand dune area
Camps or Ship Crash sites have the possibility to spawn them
In talking with people it seems they were able to have more spawned during story missions, my luck must have been bad. I did try to rest/sleep at a spot for multiple hours to try and get a respawn, but that didn't work. I also tried reloading a save to kill the same one but that also did not work. I think because it only track internally and not on the achievement tracker that it doesn't work that way
Let me know in the comments if you found other locations for them and I will add it to the list.