“He was an assassin by 1958, and he was working for the CIA by 1962-3.”
So who did “CIA assassin” Saddam Hussein kill in 1958? The natural target would have to be Abd al-Karim Qasim who somehow managed to live unscathed until 1963.
You have been conflating the coup of 1958 and that of 1963 in order to create the impression that the CIA hired Saddam Hussein to be an assassin. Your own source makes no mention of CIA involvement with the Ba’ath party prior to 1963.
The Ba’ath party did stage the coup in 1963 and they did execute Qasim/Kessem, but since they broadcast his execution and there’s no indication that Saddam was the shooter that isn’t going to help your story.
But your story runs into more trouble because after staging the coup the Baath party couldn’t gain control of Iraq. The military and the Arab Socialist Union ran it until 1968.
Did they hire Saddam to pick up groceries ?
Is Saddam an Eagle Scout ?
If I work professionally as a computer programmer starting in 2008, and the CIA hires me in 2012, might they be possibly hiring me as a programmer ?
Or would they be hiring me as a public relations executive ?