I personally like a little longer cranks. And believe that I'm happier with my legs going through a full and open movement rather than spinning in tiny circles.

The more riding I do, the better the knees feel. And, I've had times when I had been off the bike for a bit, and on the feet too much. And, a 10+ mile ride was vital for recuperation.

But, everything within reason. So your hypothetical 5'2 rider should probably be looking at much shorter cranks than someone 5'10, or > 6'.

Nonetheless, there may not be a formula that would take any rider and give their exact specs.

Perhaps there would also be some training the body to one's own bike.

So, say a bike fitter does a bunch of test on two younger 5'10" newbies, and decided 165 gave peak power for both of them. But, instead, they're sent home with one set of 157 cranks, and the other with 180 cranks. Send them out to ride 5000 miles. Then retest for power output. Will the tests all show the different riders still need the 165 cranks, or will they have habituated to what was on their bike? My guess is the riders would tend towards what they were training with.