My my, did you not watch it?
Regarding the ovens, we have a thread on the forum, I will edit this post and add it. It is also covered in the video.
Regarding the gas chamber capacity, it is addressed in the film.
Regarding cremation times, we have a thread.
Regarding your estimate of daily throughput, you are wrong, for reasons that are described in the video and also in the various threads.
In short, you can not cremate 1 body in 15 minutes, what's less 2 or more, some claim as many as 8. There is also the upkeep (fuel) and maintenance (refractory replacement for example) to consider. These are hard facts, laws if you will. You can not hand wave them away.
Cremation Rates;
https://www.codohforum.com/viewtopic.php?t=171
Refractory (not addressed in the video, but, a point not to be overlooked);
https://www.codohforum.com/viewtopic.php?t=269
The holes conundrum (not addressed in the film, but, a point not to be overlooked) ;
https://www.codohforum.com/viewtopic.php?t=180
Kula's Columns (not addressed in the film, but, a point not to be overlooked);
https://www.codohforum.com/viewtopic.php?t=163
Ventilation Capacities (not addressed in the film, but, a point not to be overlooked);
https://www.codohforum.com/viewtopic.php?t=162
The chemistry thread that existed before you made another one (not addressed in the film, but, a point not to be overlooked)
https://www.codohforum.com/viewtopic.php?t=122