This video does an alright job at explaining why the Localization is so different

[Midareyukki]

The German and French teams are internal to Square Enix. We have no indication they're managed differently.

(It's not even hard to prove. Take any of the names in interviews we posted recently in this thread and you'll see LinkedIn pages which confirms they're currently Square Enix employees working directly in the Tokyo HQ. The idea that the other two translation are outsourced is based on nothing.)

...except they ARE based on something, they're based on my own personal misconceptions, Kazhar. TLDR: I made a mistake. I was wrong.

The reason for me being wrong is because Koji Fox rarely mentions those teams, implying he's not involved in their process other than the general management of "Hey team leader, is it done? Cool, test out these bugs for me and see if they're happening in your version". Given some bugs were around, I assumed that this was an oversight commonly seen in external teams. And given how communication by Square Enix that isn't written is done in English and Japanese, it led me to think that there weren't such people in Square Enix that could provide those services.

Or at least I don't think I've ever seen any PLL being interpreted into German.

I'm not talking out of my ass, I'm speaking from what's the likely scenario based on how I understand things to work at the companies I've worked for. Good to be proven wrong. But saying "it's based on nothing" is just calling me out on bullshit. Which it isn't, it's just me assuming things based on past experiences.

But tit for tat, I'll do the same to you.

The idea that the English script is not a translation, and in fact a second master script with equal importance to the Japanese script and inherently superior to the two other translations is most likely a misconception caused by some quotes taken wildly out of context and misunderstood, then parroted ad nauseam by the community. No official source seems to support the claim. In fact, we have many interviews which disproves it.
Basically a case of "if enough people say something it becomes the truth".

No. As I stated, professionally speaking, there are two scripts. It's not something people collectively dreamt up, there are two scripts. The original Japanese script, and the changes that then occur on the English script that go beyond what's necessary in localization. The official source? We're seeing it happen all the time, people post differences in what we're given all the time in these forums. They're all over other threads on this topic.

You're right in that neither is superior to the other, but no, the English script does start as a translation, as you're taking the information from JP into English. But then you're adding stuff in and changing things past what translation work should be. That isn't normal in translation and localization jobs. So really, you're misconstruing things as well. When I say "this isn't translation", I mean it. Under normal circumstances, this isn't what you observe, this isn't what you do as a translator. This is a bit more involved in the writing process than just straightforward translation, and those additions should not be understood as part of the natural process of translation at all.

Edit: Basically the issue I have with what you wrote is that you jumped to the conclusion that I was talking out of my ass without giving me the chance to defend myself or acknowledge my mistake. (By "defend myself" I mean "to explain what led to me saying that", I'm otherwise still wrong, can't exactly justify being wrong). Even worse, you didn't even try to understand why I said what I said, you didn't realize why I was wrong. That isn't fair.
And to borrow the words you used, that sort of behaviour is "parroted ad nauseam by the community".