Here's a quick reference for finding the characters required for the Sense of Style achievement, not all are correct but I was jailing/hiring characters until I got it and overshot a little, it unlocked upon hiring Alvaro Ruiz.

If anyone finds a closer or exact combination I can redo this guide or delete on a better replacement.

(Credit S7)
List of guaranteed characters that count towards unlock:
Armando Cruz
Dulse Vega
Carlos Jimenez Morales
Miguel Angel Gacha (this character is given to you during the second plot mission)
Balthazar Pascal
Ivan Mario
& of course, Alvaro Ruiz