The million dollar question - do the GB believe their own bullshit? We can only speculate.
I think if you compare them to other cult leaders like Jim Jones for example. He didn't (as best we know) believe his own Bshit. He had brainstorming sessions to think up new doctrinal ideas. He was ultimately an egomaniac sadistic piece of....
That's what I think the GB are. Read through the latest December Watchtower and tell me that they don't know what they're doing. Pure and utter manipulation from cover to cover.
I think if the Governing Body reduced in number things would get more insular and paranoid. It will be interesting when some of them die off in the near future - perhaps if they can't find suitably sinister replacements in time the JW's may be faced with a trinity of GB or even one.. If that happens then before long I guarantee that the koolaid will come out.
The Dubs pretty much reflect the attititude of these old men, who don't have much time left themselves. They want to take the Dubs with them - and given the opportunity they will (koolaid?). If the GB were younger things may be slightly different - but that would never happen. Old white (mostly) males with big egos and zero conciences are the qualifications.