I think this is absolutely what Tolstoy is getting at. Though not all his characters get there with him — as you know because you’ve read the novel.
It’s actually this very development of character that inspired this A Year of War and Peace project a few years ago. By the novel’s end I am always struck by how the remaining characters come to live so peacefully with all the horror and misery they endured during their life. Frequent readings revealed to me that each of them seems to have gained some stoic insight into living that helps them cope. That’s why most of the meditations in this project are taken from the stoics. One of the things I’m glad to have learned from readers (Tatiana Kuzmic) this year is that Tolstoy appears to have been reading the stoics while writing War and Peace. So maybe my analysis isn’t too far off.