Bear in mind that the present doctrine of the GB depending on the F&DS class is a vestige from the power struggles between the Watchtower Society and other Russellite splinter groups in the 1920s. The earlier idea was simply that Pastor Russell was himself the F&DS and he was the vessel through which "new light" and "meat in due season" was given to the household of faith. Today the GB occupies the same theological role as Russell originally did and there was no concept of Russell depending on all anointed Christians for his "light"; it was thought that he alone held that role. Some statements published to this effect in the Watchtower were posted earlier today:
http://www.jehovahs-witness.com/6/109181/1903298/post.ashx#1903298
But in the schismatic struggles of the early 1920s, various Bible Student groups claimed authority through Russell. Rutherford used the legal body of the Watchtower & Bible Tract Society and his status as President of the corporation to enhance his theological role (whereas for Russell, his status did not depend on his being President of the corporation). Initially, Rutherford continued to teach that Russell alone was "that servant," but to set his group further apart from the other Bible Student groups he began to teach that the Society itself was "that servant", with the class of elect Christians as collectively the "Society". Thus he made himself President of the church, attaining a role similar to that of Russell, tho he did not need to claim to himself be "that servant" to have that status....rather, it was through the Society that Jehovah supposedly communicated with. Thus, when Rutherford managed to fire the Editorial Board of the Watchtower and became its de facto editor, Fred Franz regarded Jehovah God as becoming the editor of the Watchtower.
Then after Rutherford died, the board of directors then the GB began to assume more theological power, and real administrative power as well (especially by 1975, when the office of President was demoted). But since the F&DS had been democratized as a collective body rather than one person, and that body was identified with the 144,000, the GB had to claim they depended on that group for its insight, even if that relationship is totally fictive. Had Rutherford took another tack and identified the F&DS with the office of President or Board of Directors rather than the Society as a whole, then there would be no obvious inconsistency today (as the GB itself is supposed to be modeled on the apostolic council of Acts 15, which is presented as producing "new light" for first-century Christians)....