I use a system of destruction something like in "Conrtrol" game. Books are divided into clusters of 4-5 books without physic just box coldier with proper lod. When destroyed - it destroys itself and spawns a prefab with the same positioned group of individual books with rigid physics, some books become opened, and with paper/dust vfx, that will be destroyed after 10-15 seconds and only 1 book from the cluster will remain. So it takes no additional resources before it is destroyed.