I have one very simple suggestion that can resolve the problem of spies :curse: giving intell to another group.
Limited visibility for all members, :o while those who have earn trust can see the whole planing.

This work the same way as privilege in a Group (senior, anbu, etc...), :D where you entrust few members to invite new ones, kick members or give the ability to upgrade the Group.

That's a very very simple solution :lol , let Groupmaster, Seniors and Anbu be the only one to see the battle plan. Other members could be abble to see liumited intel with no names and why not something 4 or 5 minutes old. It will be impossible to use the infos. :)