Hi! I'd say you want to find a name that fits with the shorter, rough-and-tumble, surnamey feel of your other kids' names. Of your choices, I think Booker or Knox could have worked well. Atticus would seem heavy and fusty with your more modern names. What about...
Carter, Carson, or Carver
Sayer or Sawyer
Bryson or Bryce
Banning or Channing
Keegan or Curran
Garrett or Barrett
Flynn or Finn
It seems you like modern surname-names which can be a bit unisex. Are Ragan and Tatum boys or girls? Does your last name start with a C?
Names that are occupations (no Cs or Ks):
More last name-type names, with no Cs, Ks, or Ts (since you have 2 kids with T names):
Langston (like Booker, but more modern)
I really like your suggestions & will take them home to my husband!
Is Ryerson too much? And call him Rye?