How did the victorious western allies plan on dealing with the hundreds of thousands of Axis personnel likely guilty of war crimes?

At a conference, supposedly Stalin made the (probably as a joke) suggestion that 100,000 German officers be executed. Roosevelt, in response, also joked that "maybe 49,000" would be enough. Churchill was apparently disgusted by such discussions and protested against such "cold blooded killings". This likely means that mass executions were off the table at least for major powers not named the USSR.

But... there were well over 100,000 people in Germany and Japan that were complicit in war crimes. So how did the western allies even plan on dealing with them all? Was it simply accepted from the very beginning that only high profile cases will be investigated, and that the vast majority of war criminals would probably not be punished at all due to the logistics of trying to persecute so so many people?