Yes, I agree the differences between die varieties is minute for the reasons mentioned. I also agree that using die states to reckon die varieties is risky, and almost useless for early die state pieces. And yes, discerning individual dies requires finely detailed work, and the analogy with Bob Grellman's Late Date Large Cent work is appropriate.
However, that analogy also proves it can be done, as indicated by the success of Bob's Late Date book. Many other coins whose master dies were made from nearly complete hubs have die variety compilations, even coins as recent as Indian cents (with thanks to Rick Snow).
I thought I had seen a compilation of Reeded Edge die varieties as a PDF on the Heritage web site some time ago, but I can't find it now. If the scholarly research portion of the work has been done, it seems reasonable to update it and include it in the next version of the Bust Half reference.
Anything less seems unfair to a beautiful and wonderful series of coins, which heretofore have been neglected. They should have Overton numbers.