You can loosely rank folks as best as you can but its still inherently a systemic action and not based on individuals. Other factors beyond individual performance caused the layoff.

You can’t always select the bottom 20%. Sometimes, whole teams or departments are eliminated. Employees are simply a number with cost and only thing matters is cost. They almost never look at individual performance or productivity.

If your manager or director is not getting laid off with you and you have a good relationship with them, then they might fight to keep you.