So this is a third test 'mod' to try, after removing test 2. I have removed the timecode data from the AOS bow shoot sounds, and resaved them as. This is obviously not a problem for 99.9% of users, because people would have posted comments immediately, but maybe it doesn't work on your system for some reason.

I looked at them in an audio editor, and discovered they have an extra 'track' of information, which is a timecode. I'd love a link that explains more about this phenomenon, just for future reference - thanks for the now we know that only the AOS sounds are not working for you. That's the first I've heard that BSAs could overwrite loose files in Skyrim. Improper AI will cause BSAs to overwrite loose files, so the vanilla files would overwrite the mod's loose files.