To this outsider, your question sounds like exactly the reason Google needs this sort of process. Even if an employee were working in an area that was theoretically competitive with something, an official determination by Google should trump theoretical arguments - providing valuable certainty to both sides.
We have a small group from code of conduct/conflicts, open source, android and folks who represent a few other strategic groups at Google and we simply requests one by one. Most of the time it isn't a problem and we grant the request. Getting everyone together regularly can be a bit more difficult, that's why it takes longer.
