The idea that some sort of complex algorithm should be used indicates a misunderstanding of what business management actually consists of.
It is much more social science than engineering.
Yes, in this case the corporate goal is to fire 500 people as a sacrifice to the finance gods.
If the goal was 'refocus strategy', you'd probably want to actually assess your business and determine who is no longer necessary, and you would doubtfully end up at a nice round number
The question isn't "who is no longer necessary".
The question is "do we think we can cut 500 roles (Y/N)"
The 2nd question is a reasonable and useful business assessment. The first question is not relevant and has no real answer.
Leadership, based on their understanding and information make the decision to cut 500 and create a mandate to make it so. Then management is forced to decide who gets the axe.
It would basically be impossible to drive the decision the other way. You can't asses every individual for necessity. What would the threshold even be? The threshold depends on the number of people you want to fire.
There is no super computer that can calculate the outcome from firing \ 499 workers vs 500