A revisionist historian reads at least a dozen books, or in the case of the Kennedy assassination, maybe a hundred books. He begins the study of the Kennedy assassination with a detailed investigation of the Warren Commission. He has to read everything connected with the Warren Commission and then begin his questioning in response to those documents. A conspiracy theorist has probably never read the Warren Commission report, let alone the support volumes.
When somebody questions almost every official account of everything, you know that he is not a revisionist historian. He is a conspiracy historian. It takes too much work to study any major event in which there may have been a cause that is completely different from the government's official version.
When it comes to explanations other than the official explanation, I prefer to wait for a heavily footnoted book written by somebody who has written a book on something else, and who has demonstrated in that book his ability to research evidence and draw plausible conclusions from the evidence. That is hard work. Somebody has to be dedicated to do this kind of work.
The crazies live in a world of self-induced fantasy. They do not accept the validity of historical cause and effect. They do not follow the money, or the confession, or the media back to a source. They are unwilling to make the commitment to any verifiable truth. They prefer to move on to a new conspiracy.
The greatest revisionist historian was Murray Rothbard. He was an economist. He looked for economic motivation. He followed the money. He followed the publications. He followed the meetings. He named names. He did his homework. Then he provided plausible arguments for causation. He did not promote the idea of a single conspiracy. He showed how self-interested people used state power to feather their nests. He did not accept official explanations.
Rothbard understood a fundamental point: conspiracies gain their leverage through political power.