You don’t have to provide a complete ranking of candidates. You only have to decide which candidates to accept and which not to in the bucket that you would prefer to randomise. And it seems to me that such decisions could in principle be made extremely quickly, particularly since you must already have assimilated some information about the candidates in order to put them in the right bucket (though speed probably affects quality adversely; but I still think some signal will remain).
You don’t have to provide a complete ranking of candidates. You only have to decide which candidates to accept and which not to in the bucket that you would prefer to randomise. And it seems to me that such decisions could in principle be made extremely quickly, particularly since you must already have assimilated some information about the candidates in order to put them in the right bucket (though speed probably affects quality adversely; but I still think some signal will remain).