My approach is to reverse engineer the Big Event since there is enough evidence for me to conclude this was a conspiracy and Oswald was the patsy. That is my starting premise and I work backwards to make the tale fit the evidence. A coup always happens from within, by those who have the motives and wherewithal to make it happen. Only the top men could have pulled this off and kept it a secret. But you only need a hand full of people to make it work if their marching orders come from the very top. Besides who would believe them if they spilled the beans? Perhaps those that tried are swimming with the fishes.
Why doesn't anyone believe E. Howard Hunt's confession, or James Files, or Roscoe White? Is it because Allen Dulles, James Angleton, J. Edgar Hoover, and Lyndon Johnson were saints and would never participate in a coup d'etat, unless the POTUS really had it coming? Richard Nixon thought they were animals capable of anything. He knew.