Here's a little theory about how the GB selections go down and how that contributes to there being little to no substantive change.
First let's assume GB members are appointed on a 2/3 majority vote basis. Let's also assume that there are important changes that are being held back because a 2/3 majority hasn’t been achieved. That's akin to giving the 1/3 minority a veto. The minority could similarly exercise such a veto if they had reason to suspect a new GB member would not side with them on contentious issues.
So there's gridlock until the 1/3 minority feels sufficiently secure that a potential new GB member will side with them in preserving the status quo. Perhaps little heart-to-heart talks with short-list members every now and then to get their view on things. Therefore, nothing really new is ever introduced.
Hence, slow death by bureaucratic asphyxiation is the likely outcome for the group.