Serious question about stone sword keys

I recently finished a DoN run where we hit 7 evergaols. That sound all fine and dandy except we only went to one fort and starting camp with a stone sword key. And of course we all started with one so that’s 5 keys. We don’t go to any great churches, so where did the other 2 keys from. Was that cheated or am I missing a possibility. I rewatched the footage twice and still have no idea how we had that many keys