Anyway, most people just spout that DQ is so much more popular than FF in Japan because DQ doesn't sell as well anywhere else as it does in Japan. In reality, there is not much difference between FF and DQ in Japan.
Only a few hundred thousand difference on each one, except the third, which has a .6 million difference.
I'm curious how being on a handheld will make a difference.
That's not true at all, there is a very large sales difference between FF and DQ, because FF is in a huge sales dive. If you compare the last FF, FFXII at 2.42 million vs. DQVIII at 3.61 million, you are looking at 43% difference in sales.
As for how being on a handheld will make a difference, it's the DS. The DS is a phenomenon in Japan, with core games and casual games alike selling like crazy on it. New Super Mario Bros. sold 4.75 million on the DS in Japan, Pokemon Diamond and Pearl sold 5.29 million in Japan. Do you really see one of the most popular franchises in Japan underselling it's predecessor now that it's on a much more popular game system?