In relation to in-character PMs, the Thieves Guild PM is completely in character. Everything is planned in character, other discussion is in quote boxes, and it works. So yeah, I have no hesitation saying that this works as a great model for guild PMs and planning in general.
The thing is, most guilds don't see a need to have leadership in the same sense of the GBs. Sure there is a stated leader, but nothing really is affected by it. That does go back to the way the guilds are run and as I said before, most don't have the GBs hierarchy, so for most of us, the characters don't need a specific "position" or "level of importance" since there's a feeling of equality. Sorana's really describing something that only ought to apply to one guild (unless the DA has some secret ranking system.)