The need of repeating exactly the same destructuring or transformation (keys, uncurrying tuple) constaints your thought. You need to have an instrument that fits your domain perfectly.
group-by-[12] groups a [[k, v]] list by either k or v, of course you can do this with group-by first, but see above.
group-by-[12] groups a [[k, v]] list by either k or v, of course you can do this with group-by first, but see above.