You haven't described a 'manga style' - you've described a particular group of schools under the 'manga' umbrella, and you admit yourself that they share those same elements with styles that nobody ever calls 'manga'.
Which is why I mentioned multiple. It is not one or two causing it to become Manga, but the confluence of the three listed and more.
Seriously, look at the three books I note - they are NOT the same style with small differences, they are three completely different styles, one of which is a deliberate rejection of the influences the other two have in common.
I disagree. Infact, in the wiki images, the non-sequential requirements are obviously there. Eye Emphasis and Deliberate Simplicifaction/Detail dichotomy are both present in all three. If that's not enough (and I did say it would be a confluence of 3 or more to cause it), then I'm sure we can dig up some panel segments that'd apply to the transitions I mentioned. It's a checklist. Use it as such. You cannot deny that there is deliberate use of Simplification/Objectification (Fist of the North Star too, I know you're going to claim otherwise, but the cleaness of the heroes face says otherwise) in the three works used, nore can you deny the eye emphasis in the character designs.
Calling them 'the same style' is exactly equivalent to calling them the same style as Walt Disney or Hannah Barbera.
Style is a wider umbrella than "Artists" or "Animation House".
Perhaps we should define the term "Style" as applying to a larger swath of changes and use the phrase "individual style" for smaller distinctions.
Though, if you wanted, you could probably get them to be divided into more specific styles of "Wester Film Animation" and "Western Television Animation".
And yes, both Walt and Barbera would fall under Western style art. Their origins (Rotoscoping vs. the quest for cheaper animation) make their styles quite unique and easily seperatable. A few outstanding examples (Jonny Quest) buck their trends, but are still identifyable as Western (or, really, American) Animation.
And I've read Understanding Comics, and I am perfectly aware of Tezuka's influence, and the influences he drew from - neither suggests that everyone who came after him is the same style.
Except history. Ya know, those epithets such as "Father/God of Manga" couldn't POSSIBLY mean that he had influence on the style. Nah. That couldn't possibly be the case.
From where I sit, a lot of the Manga is Only Japanese! outcry is the same sort of misplaced obsession with Japanse culture that results in fansubers being utter failures as translators by leaving words they like untranslated for some misconception about things such as "Sama" or "Nakama" being Untranslatable.