So really the scale and Gauge can be the same thing it just depends on how you want to split hairs.
No, they are fundamentally different things, and this is not splitting hairs. One is the difference in size between two similar objects expressed (generally) as a ratio, the other is the distance between two different rails expressed as a linear measurement.
American O gauge (Tin plate) was 7mm to the foot scale and HO was half of that gauge/scale or 3.5mm to the foot it is fact. So do not try to rewrite history to suit yourself.
Telling us not to rewrite history whilst rewriting history and geography by yourself? That's a new trick! Got some Yankee 7mm to show me? I suspect not. I think you might go closer to the truth if you go looking at the other side of the war... While on the war thing, you might also like to consider after which war H0 came to popular use about the place, but I don't know, maybe II comes before I occasionally.
Tinplate here is the likes of Lionel, Bing, Hornby and plenty of others, there was actually no consistent scale in these different brands but again they all ran on O gauge track.
There need not be a consistent scale, once again, it's the name of ... A GAUGE...
Also how many different scales are there for N gauge while we are there, America has on size Europe has another, Britain has another and Japan has another. So what is the correct scale/gauge for N who got it right!
You've not been reading properly again. It's SANGS, not SANSS! N is a gauge, not a scale, it's 9mm track. Who got it right? That's not the difficult question you think it is, the answer is whoever got their tracks to be 9mm apart.