John,
Since they didn't even know if Oswald would show up for work that day (or be captured on film, outside, during the shooting) the evil, evil, evil S.O.B.s in CIA didn't know if they'd be framing Oswald, or Joe Molina, or Jack Dougherty, or that vicious little Vicki Adams until after the smoke had cleared!
LOL
-- MWT
Hi Thomas, that's an interesting scenario, Oswald didn't see Marina the weekend before and could have rightfully made it a long weekend to make up for the lost time or Oswald could have been sick or involved in a car crash with Frazier or any number of problems but everything goes to plan and Oswald goes to work and stays out of sight at 12:30, what are the odds the random person "they" pick would tick so many boxes?
Your what ifs are interesting, Jack Dougherty would be the no brainer, mainly because many perceive him to be a bit slow which would make later manipulation much easier. Dougherty gets to work early so getting a rifle into the building could be easily explained, he was in the service, lived at home, never married, classic Loner.
JohnM