If you were on the GB, and you wanted to push your own personal agendas and doctrines, wouldn't you want to resist adding any new members.
When there were 10 members, basically each member has 10% control.
Now that there are 7 members, each has basically 14% of the vote.
Adding more members dilutes your power. And if you truly believe the "overlapping" doctrine, there isn't really a valid reason to add anyone else, if the overlapping is applied to GB 1.0 and 2.0 only.
If another one dies, then basically you only need 4 votes to top the other two votes, that is pretty small power center, only four men.
Will be interesting to see if they wait a while to add anyone else.