IMO, at least for one who has collected for 50+ years scale and size are never confused.
Manufactures started with the scale. 172, 176,etc....based in part to show the item as it related to HO scale railroads
Then Airfix did that OO scale thing. Then came the, to be brief, european sizing. All in MM and no longer as simple to figure out.
Now in our toy soldier world 172 is used. But that can mean anything from 22mm to 27mm.
The point was Not various manufactures do their own thing but they do not keep the same size, scale, whatever within
their own output.