OK then please correct me. I do not want to create misunderstandings.
As I understand it, I can line up 5 balls across the table between the side pockets and line up 5 cue balls at the head string so that each set of balls is parallel to the side rail. I'd reference Stan's youtube video on perceptions but he deleted it after so may years. So, anyhoo, I can shoot all five of these set up shots in the same corner pocket with the 15 degree (ETA) perception and an inside sweep. All 5 are done the exact same way, same sweep and every shot, each of which are different shot angles, will go in the corner pocket. This would be an objective system.
Now, is that no longer correct, and now some sort of artistry needs to be applied to this process?
First off those 5 shots will be broken down in detail in The Book.
Second off, see how you misinterpret things. NO ONE said any kind of artistry needs to happen for CTE to work 100% objectively. It's established that the instructions are objective and if followed exactly you will get the expected objective result. The only thing i said is that pool is an art. Are we playing 100% objectively, NO. We are playing pool. Doesn't mean we don't use objective instructions to get our visual.