FFXV 24-hour shipments+Digital = 5m.
Current LTD = 8.4m(PC/PS4/XB1).
I don't think 10m is realistic for a single player JRPG if FFXV is struggling to reach that sales number. This isn't the same as MHW situation where the potential of sales was held back by the hardware and region, multiplayer focused games tend to do better in the west.
KH3 isn't going to outsell FFXV and nowhere near MHW numbers.
I never understood this FF XV comparison.Why FF XV selling 8.4 million will stop KH III from doing better than it?Because its a better known franchise?That argument is bad for several reasons:
First, FF has fallen from grace.That is a known fact.The last masterpiece to ever grace FF was FF X, and ever since then, the franchise has been losing steam, at least in terms of how it is perceived by the public.FF XV might be the third best selling entry(?), but thats after three different versions hit the store shelves.(The vanilla one, Pocket Edition, and the Royal Edition)The only reason FF XV is "struggling" to reach that number(8.4 is an excellent number, even if thats I dont like that) is because the game is not good.
Second: Many single player games have been performing incredibly in the 8th and 9th gen(Switch is 9th gen).Persona 5, Nier Automata, MH World, Xenoblade Chronicles 2, Dragon Quest XI and many more have been doing far better than what their franchises usually do.Not only that, but KH is arguably better known than most RPGs(Japanese or not), so it has a bigger chance of success either way.
Third: KH 1 and 2, if Im not mistaken, have sold a bit more than 6 million each.The collections did about 2 millions each.Assuming that KH III will do 10 millions lifetime, after years of being on the market, dosent seem far fetched to me.
Fourth: As I said, quality is very important nowadays, on an age where information is far more easily acessible than it was 15 years ago.This makes word of mouth far stronger and important for a game to sell itself.FF has been in decline for years now(and FF XV didnt change that), but KH has maintained its pedigree for the most part.If KH III is very well received (Metacritic of 85+), then there is no reason to expect that it will do less than FF XV, at least not for the reasons you presented.
Fifth: KH has the Disney appeal to help sell it.Not only that, but it has popular Disney IPs on it(Frozen and Toy Story just to name a few) that might make it a better sell than FF nowadays.
And those are just a few reasons that KH MIGHT beat FF XV sales and reach 10 millions.For years now, KH has been one of the three Square flagship franchises (FF, KH and DQ).People need to stop getting so hang up on past data and franchise pedigrees and start looking more on the circunstances around the game and the current market trends.Just to give a quick example: MH World wasnt being held back solely because of the hardware it was in.MH was once in the PS2 after all, and the PS2 sold 150 million units by the end of its life.MH World sold like it did because of two simple reasons:It was a multiplatform game, AND it was an excellent game, much better(both in quality and innovation) than its predecessors.Simple as that.
If KH III ends up being as good as I think it will, ohhhh boy.... The only thing that might hold it back selling more than it will is the story, since you need to have played 6 and a half games to understand it(Im not counting Coded and Chi in kind of a half game, being a mobile game and all).