Didn't realize I opened up such a Pandora's Box.
Yeah, definitely.
I'm saying that because the overall sales are so large, there could be pocket of 1-2 million more "hardcore" who do infact buy pokemon along with the Bravely's, SMT, M&L, etc.
And that 1-2m hardcore who buys other games would basically be comparable with any other JRPG currently.
Obviously I don't know for sure if it exists. (Places like GAF lead me to believe that group does exist though) but again I don't see that scenario as much more unreasonable than the opposite being true (i.e. pokemon's total audience almost being completely totally separate from JRPGs in terms of buying practices.)
The one thing that Pokemon (and Yokai to some extent) has over most other releases worldwide is that it is targeted and played by basically the entire age spectrum. Obviously this means a lot more casual play is involved in such a title (and with those numbers, this is obvious) and it also means that kids enter the pool for the genre and can become long term members of the audience.
This in turn leads to the relatively consistent sales of more kid-oriented titles like the Mario RPGs (Paper and M&L) and spills into the various but still continuing flow of kid friendly titles. On the other hand, more casual players who also dip their toes into the genre with Pokemon, will show up for titles like Fantasy Life or Rune Factory (since both are now RIP, Nintendo seemingly decided to make their own) which blends more casually friendly elements with RPG mechanics. And then, obviously mixed in with all of this, is the core that buys just about everything jRPG to some degree though even in there there's obviously a split. Fire Emblem falls somewhere between casual and core nowadays, that's why it went from a few hundred thousands to ~2million seller.
Basically, if we made a ven diagram, Pokemon would encapsulate just about everything, and inside of it would be stuff like Yokai, FE, Fantasy Life, and the Mario RPGs, that all have their own circles that overlap to some degree, and in the core is... the core. Probably have a circle purely for the ATLUS crowd.
Part of the problem with the modern jRPG genre (and in general a symptom of the endemic problem in the Japanese industry) is that it targets fans. It targets the diminishing pool of an audience. Dragon Quest Builders is one of the few entries to eschew that outside of a Nintendo product.
Final Fantasy does similar things, or did, anyway. I am still very dubious of how this new FF will be received and if it won't just slot into the traditional "WRPG" slot with some "Japanese design quirks". It feels like its trying to be a WRPG rather than a JRPG in the traditional sense.