I don't agree.
I believe Hitler and his killing crews sought to make it easy on themselves while killing ten million Jews in cold blood, by not regarding them as ten million different individuals but merely as one great big reified lump, an ethnicity.
I don't believe that Hitler and his crew could have killed more than a few dozen a day, and even then only once in a while, if they had to sit behind a desk and look at the photos in hundreds of dossiers, devoid of ethnicity/religion /politics and decide which ones of those individual faces lived and which ones died.
Even Stalin, a very hands on guy when it came to the execution of the elite of the USSR, found it tough to do this sort of work all the time.
He often avoid all that hard thinking and deciding by simply issuing an order to the NRVD directing that all POWs with the simple label, "Polish", must be killed by next week.
Then he went off ,with a bottle in hand, to relax by watching a Hollywood comedy.
Sixty million individuals were killed in WWII ,including six million Jews - smoothly and easily - by deliberately not regarding them as sixty million highly different individuals.
We must not let WWII like thinking slip in sideways by letting historians reifying Hitler's victims into a few big lumps.
We must always seek to unbundle their lives and the lives of those 'much like them' who did not die, back into individual stories.
We must always remember that individual killers killed individual victims and overcome the easy (bottle in hand/Hollywood comedy) solution of simply assigning collective guilt to account for collective horrors and calling it an academic day.
Only in Hitler's mind, did one reified lump called "all Aryans" want to kill another reified lump called "all Jews"......