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'.
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.
Calling them 'the same style' is exactly equivalent to calling them the same style as Walt Disney or Hannah Barbera.
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.