Two things...
One of Din's group is a Vizsla. Given the Protectors' reaction to Sabine saying she was House Vizsla, I'm gonna guess they're not too popular in Mandalorian space during the OT era. Death Watch essentially split during the tail end of Clone Wars, with many siding with Bo-Katan and dialing back the extremism, and some sticking with Maul and going off to bust him out of prison. I feel like there had to be at least a few who felt stuck between those extremes... and just left. This group may be from that time.
The other thing is that, at the end of Rebels, Sabine is meeting Ahsoka on Lothal to go look for Ezra, and her narration is one of everything being hunky-dory. I figure at that time Bo has the darksaber, the Imps are off Mandalore, and she feels it's quiet enough to go on a personal quest. This series is about five years later. Perhaps the Purge happened in there, and -- from the dialogue -- Moff Gideon was involved. The group on Navarro could be survivors of that, or they could already have been off-planet and just heard about it. I figure we'll find out more further in. I don't expect contratictory lore, given Filoni's oversight on all three series...
One of Din's group is a Vizsla. Given the Protectors' reaction to Sabine saying she was House Vizsla, I'm gonna guess they're not too popular in Mandalorian space during the OT era. Death Watch essentially split during the tail end of Clone Wars, with many siding with Bo-Katan and dialing back the extremism, and some sticking with Maul and going off to bust him out of prison. I feel like there had to be at least a few who felt stuck between those extremes... and just left. This group may be from that time.
The other thing is that, at the end of Rebels, Sabine is meeting Ahsoka on Lothal to go look for Ezra, and her narration is one of everything being hunky-dory. I figure at that time Bo has the darksaber, the Imps are off Mandalore, and she feels it's quiet enough to go on a personal quest. This series is about five years later. Perhaps the Purge happened in there, and -- from the dialogue -- Moff Gideon was involved. The group on Navarro could be survivors of that, or they could already have been off-planet and just heard about it. I figure we'll find out more further in. I don't expect contratictory lore, given Filoni's oversight on all three series...