I agree with markweatherill. If the GB are the "evil slave", then that would have to be all of them collectively, as the slave (if it's a collective body at all), is spoken of as being either one or the other.
As said, if they are the evil slave then they won't accept it anyway until it's too late. It parallels Matthew 22 where the man who arrives for the wedding feast isn't wearing the right garments: he thinks he's entitled to be there, but is not properly dressed. He's not "put on" the "clothing" that he should have done - not displaying the right qualities (the Christlike personality that is spoken of as being like a garment), and so the man is showing disrespect to the Groom. So he's shocked to be thrown out by the Groom when He arrives.
As to whether the GB know what they are doing, I think that while some of the changes they are making are right - removing Pharasaical rules about beards, ties, dresses, reporting hours, etc, for example - they are still culpable because they have not changed more serious matters that they know are causing problems and that they are failing on, which are causing real distress in congregations, such as tackling genuinely wrong behaviour (there was a thread about "engineering divorces", for example, which we know goes on and the GB has done little about it), including the painful results of judicial injustices, wrongly disfellowshipping, shunning and the heavy-handed application of internal "rules" which are not supported by scripture, etc.
It's like Jesus accused the Pharisees of "straining out the gnat" but "gulping down the camel" - worrying over petty details, (like adminstrative and procedural stuff, what outfits can be worn, which form to fill in for which assignment, etc) but missing the "weightier things" like justice and mercy.
IMO, that's also why, despite the tinkering they are doing that they think might spare them the wrath of governments (eg: the Norway case), I don't believe they will be allowed to get away so lightly.,
I think it's interesting times in JW-land, and not necessarily for the reasons the GB expect. Watch this space!