How many Germans/Japanese committed war crimes in WW2, is there even an estimate as to how many questionable dudes were out there?

500 Germans were executed for war crimes following WW2. A thousand Japanese followed suit.

(Soviets killed thousands of Germans and apparently 3000 Japanese, but these trials were shamtastic and no one seems to have wrote down what exactly was done.)

Of course this is a tiny tiny percentage of those that actually committed war crimes in WW2. 200,000 people were said to have been involved in the holocaust. There were 3,000 members of the einsatzgruppen, over 10,000 kempei (Japanese military police), almost one million SS.

Is there even an estimate of how many people were involved in war crimes, if at all? I found that at least for the Japanese the initial estimates taken around 1943 were around 500,000, but this kept getting reduced as the war progressed and eventually under 5,000 were tried.