[Anglachel]

Or simply not have temples auto-destroy upon conquering of a province. Require a commander to take out a turn to dismantle it much like someone dismantling thier own buildings in thier own province. Make the timing of the dismantling of said building take place after movement and combat giving time for trying to retake the province and protect the temple. Of course this wouldn't really solve castling but would remove the need to use castles to protect temples somewhat anyways.

Just a thought.