Do You Think Oswald Was a Hero?

Walsi and Pachepa write that Oswald had demonstrated to the KGB officers in Mexico how carefully and successfully he had planned to take a shot at General Edwin Walker on April 10th without leaving any telltale evidence. They see Oswald as going to Mexico City to provide evidence to his handlers that he could pull off the Kennedy assassination, even though they ended up calling it off. Do you see any additional evidence that supports their theory that the Walker shooting was a test?