I had already seen your interesting post, which prompted my rather simplified question which I purposely posted in another forum.
Let me translate that.... you read Bergerie1's post which gives you an insight into the real life decisions behind routing and that its more than just reading the NOTAMS. But instead of accepting that, you can think you can do better and second-guess the airlines when you've got access to far less information than they do.
As you have also been told by Hotel Tango, routings are changed on a day by day and even hour by hour basis.
In other words, your quest to second-guess the airlines is over before it has started.
In truth, this leaves the average SLF customer with just trusting the airline's despatcher.
Short of setting up your own airline and flying the plane yourself... yes. You have to trust the airline and its staff.
This is not easily acceptable
So the truth is not acceptable ? Well, no matter how many times you repeat the question, you won't get a better answer.
As Hotel Tango on the UPS218 thread said....
posters like you are a pain. You ask a fair question and you get good answers from professionals. But that's not good enough and you need to ask what is basically the same question again!
As I said above CISTRS, pick an airline you can trust and "You pays your money and you takes your chances"