unfortunately, this issue is an obvious victim of "local" / "common" / "name"
bazillions of "same things" go by local usage names.
and "same things" is not identical to "same cut" - a definition of 'wide flat muscle cut' can pertain to a gazillion bits and pieces of an animal.
I've seen the same issue with "flat iron steak" - it was "recently invented" - uhmmm, the cow is not exactly "recent" . . .
and the variations offered on-line absolutely prove . . . . just not the same thing here . . .