ParanoidObsessive posted... But then they had the problem of American audiences wondering why the hell the game jumped directly from 1 to 4. So they just renumbered it, because what difference did it make? Americans wouldn't know any different. Just like we didn't know that SMB2 was secretly Doki Doki Panic or that Final Fantasy Legend was really SaGa and Final Fantasy Adventure was really Seiken Densetsu (Mana).
Final Fantasy Adventure is not truly an example of rebranding for localization outside Japan, despite frequently being cited as one. Its full title in Japanese is
Seiken Densetsu: Final Fantasy Gaiden, and it was branded as a spin-off of Final Fantasy in Japan. They simply shortened the title for international release (liberally translating
gaiden as adventure). It was when the sequel was developed that the series became independent from Final Fantasy.