I personally think DQ5 on SNES would have made a big difference. It was a very strong game and a lot of folks were playing SNES RPGs.
I doubt it would have made much of a difference.
No one was playing JRPGs on the SNES. Someone with numbers can clarify things, but I think that Super Mario RPG was the only SNES JRPG to break 500k in the west. You can see numbers for the Square stuff.
Either Gamepro or EGM used to shove RPGs into their own little ghetto segment at the back part of their magazine during that era, because the games weren't popular enough to warrant better coverage.
Maybe more people would have remembered Dragon Quest when DQ7 was localized, but even then you have an archaic looking game trying to compete with Chrono Cross, FFIX and X.
EDIT: JRPGs seemed bigger than they were in the late 90s/early 2000s because the small handful of series that people actually played were getting regular mainline releases. Everything else has been as niche as ever. You can count the non Pokemon/Final Fantasy/Kingdom Hearts/Mario JRPGs that broke 500k in the west in the 90s on your hands. Adding in your toes might get you through the PS2 generation as well.