What was the experience of people who entered Auschwitz in July 1942 or later, in comparison to the 1.2 million jews who died in the 9 months leading up to that point?

The first massive killings of Jews took place in September 1941, and the large systematic mass killings began in March 1942, with the majority of jews deported to Auschwitz being gassed almost immediately and the majority not being used as slave labor.<br><br>However, at some point in July 1942 Himmler ordered that each trainload of jews deported to Auschwitz be divided and split between labor and gas, and the first selection of this kind occurred on July 9 1942.<br><br>So for the jews who were deported to Auschwitz after July 1942, then the routine was:<br><br>* train arrives<br>* people are crammed into the train station<br>* people are ordered to strip<br>* people are ordered to split into men vs women<br>* first selection between labor and gas<br>* people taken to the gas chambers<br>* people selected for labor receive medical testing and if they are sick, they are gassed<br><br><br>For the 1.2 million jews who died in the 9 months leading up to this point, they were most likely deported to Auschwitz and gassed almost immediately with only the most healthy selected for slave labor camp.<br><br>So for the 1.2 million jews killed in the first 9 months of mass killings, their experience was to be crammed into a train station and gassed almost immediately. But for the hundreds of thousands of jews deported after that point, they had the same experience as those above, but with the added selection and the added medical testing and visit to the infirmary. Is that correct?<br><br>I'm trying to understand here because it seems like each of these two groups of jews basically had different experiences and i want to understand more precisely what the camp was like at different times.