Lots of excellent data in this thread. Numbers and comparisons everywhere. I like it.
One completely pointless comment that I'm going to make because I can is that I'd love to see a software swap between third parties on the consoles. It'd be so interesting to see what the 3DS' top 10 would sell on Vita and vice versa.
For example, I think Monster Hunter 4 would have no problem reaching that ballpark figure if it had released on Vita. Yes, I know, Vita has low install base. But if people knew Monster Hunter was coming, it would've been a hardware mover from that + when it released. We know that IP pretty much single handedly can save a Sony handheld in Japan if it needs to (evidence: PSP).
Same with Dragon Quest. Insanely popular Japanese-focused IP. I'd imagine it'd sell like hotcakes no matter what it released on. Perhaps not if it was Xbox One exclusive, but pretty much everything else would be no problem.
The others... not so much. LEGO doesn't sell on Vita now so Star Wars 3 wouldn't have been great. Sonic wouldn't have done well as a late port and in a genre that hasn't exactly flourished on Vita. Layton is basically a Nintendo second-party game anyway (I know it's not, but still).
However, I reckon Resident Evil Revelations could've done comparative numbers, simply because it is an IP which has a long association with Sony and it is an IP which can sell well in all 3 regions. Same deal with Kingdom Hearts.
And in reverse - well, I reckon God Eater 2 & Ragnarok Odyssey would've done excellently on 3DS given its dominance in Japan. Probably Persona 4 too, although that's another one that has pretty traditional ties with Sony so it would've been interesting to see how it did.
The other games, however, I can't really see having done any better on 3DS. Which has FIFA and it doesn't sell too great. Same with Rayman. Same with Need for Speed. Assassin's Creed & Call of Duty would be interesting examples, but if you use the DS versions as a precedent then I don't think they would've sold notably better on 3DS.
Point I'm building towards with this is - these software sales are pretty much a matter of construction. So many of these are IP's that will sell pretty well just because they are what they are - big, traditional Japanese IP's with either worldwide appeal or extremely strong native appeal.
And that is a massive factor in where Sony went wrong with Vita. Look how many western games are in the Vita's top 10 compared to 3DS'. Sony should've been courting Capcom & Square Enix to make games for the Vita because they'd have taken care of themselves in Japan and helped out worldwide too. Instead, they focused on the west which is a market which traditionally - and now more than ever - has never cared about handhelds.
And without Sony's courtship, they went to the handheld which would sell well anyway on the strength of first-party IP's. Which of course, was a pretty smart move in the majority of cases.
