Bush may or may not have been inept; on that we will actually will have to wait for the verdict of history. Cheney was however one of the most stunningly successful senior executives in US history, getting more of his agenda accomplished than any other President except FDR and possibly more than him as well (so much is still classified so we don't and may never know). To call Cheney "stupid" or "inept" is, well, foolish.
And if it is impossible for a large group to keep a secret in Washington DC, answer me this: besides Libby, Addington, and Yoo, who were the other 37 members of Cheney's staff from 2001-2009? Oh wait, their names, salaries, titles, and duties were kept secret for 8 years, Cheney used his self-granted power to classify the information secret, and it never leaked. Nor did the members or agenda of Cheney's 2001 oil conference ever leak. Again, after the events of 2002-2006 to say it is not possible to manage a secret concerted effort in DC is foolish.