Pre-war recreational battles inside of one'a clan
I think that an interesting idea would be to allow members of your clan to have the opportunity to attack members of your own clan during preparation day of any clan war. The benefits of doing such, would be that clan members could help have a better idea of what flaws there base might contain, and what is the most fortified part of your base. Of course these attacks would not count for or against your clan, they are purely for recreational and educational experiences. Also no trophies or loot could be deducted from the base that is being attacked, nor will there be any sort of boon for successfully defending the onslaught of a rival clan member.