After doing some more snooping and article sleuthing?
Here's some more character info I pulled together for Season 3 of FTWD:

1. Michael Greyeyes as Qaletqa Walker.
Mr. Greyeyes is a very much respected Native-American actor.
From the looks of it in the latest "Chaos" promo? Michael's character is the leader of a community who is butting heads with the Otto's militia.

2. Justin Rain as Crazy Dog.
Justin Rain is a young Canadian actor who is known for a lot of TV dramas.
His character appears to be strong follower of Walker's. Maybe possibly his son?

3. Jason Manuel Olazabal as Dante Esquivel.
Jason is a character actor known for his short performance on "Dexter."
It would seem that Dexter is an un-savory villain who has taken over Lola Gurrero's dam and has evil plans for it.