It’s not universally solvable - that would be my observation. It’s also contextual - some things index more naturally than other things, or rather, some indexes seem intuitive for certain objects, but the same method can seem counter-intuitive for other objects.
I’m looking forward to seeing you struggle with this… clever man, difficult problem. Entertainment.
As it happens I was a Knowledge Manager for a Fortune 500 company and have designed, built and maintained taxonomies for many years. It is quite an undertaking to make them useful and understandable by ordinary users.