It is good to know somebody else is using the S_BTCH_NAM solution because that is what we have been doing. I just don't like giving that auth because our permitted userID has a lot of authorizations, but I suppose it's better than attempting to find every auth object needed across all the business suite products where they archive (CRM, SRM etc). I did not know about table ARCH_OBJ. Very interesting. And it's a nice trick to search TSTCV for SAPMAADM, I hadn't thought of that either! So we have some options now in case the archiving team complains about the S_BTCH_NAM approach in the future.
thank you Colleen and Otto!