Have we not seen the legs for Zelda and Splatoon? Both are constantly in the top 20, while splatoon has even reached number one in Japan some 30 weeks after launch. Mario Odyssey has already surpassed a million copies this year, I don't see how you think 15 million is the max it will reach. And besides, we have to remember that this all happened in 15 months of the switch life. Based off of what we have been seeing, Switch games have been more desirable than past iterations. It is not unlikely to think that something like Animal crossing will be the best selling version of it's series. And Smash? It would be weird to have smash typically be a bigger seller than zelda and Mario just for those two too outsell it now. Especially the Ultimate Smash game, and the biggest title by far this year.
As for the sony's titles, how am I using wishful thinking, when you just implied that Uncharted 4 might have 15 million sold? The last update was 8.7 million right? How is it crazy that a Nintendo title won't have legs to reach 20 million when it sold 11 million in 8 months, but it is ok that Uncharted could have reached 15 million? If it takes by the end of the ps4 5th year to have 5 titles pasted 10 million, when the Switch will possibly have 5 titles pasted 10 million by the end of it's second year, it is quite easy to see why they aren't on the same level
Oh sorry, I meant for Mario and Zelda after this year, my bad for not explain myself correctly.
In respect of Zelda and Splatoon, yeah, they are normally in the top 20 this year, but Zelda must be around 10m and Splatoon 2 around 6-6'5m. They will probaly sell only in 2018 around 3m each, but I expect them to fall considerably in 2019 once Smash Bros, Pokemon 2019, Metroid Prime 4, and more new games start arriving to Switch and make the competion harder.
And about Uncharted 4 sales, I based that number because the 8'7m figure was at the end of 2016, but we have another number after The Lost Legacy launched, at the end of 2017 (December 11) where Sony stated that Uncharted franchise had sold almost 42m, when in May 2016, just before U4 launch the sales were around 28m. So U4 and TLL sold around 14m sales in that period. So, maybe Uncharted TLL sold a lot better than most think and in less than 5 months sold more than 4m units, or most probably, U4 sold most of those 14m units. Now we are in August 2018, so i'm pretty confident U4 is around 10-15m (i'm using a range, i'm not saying that it sold 15m, I think it must be around 12-13m in fact)
And yeah, Switch did those number of sales in just 2 years comparred to Sony, but PS4 has in the future Ghost of Tsushima, another TLOU in part II, and i'm pretty confident Days Gone will surprise in terms of sales. We are not comparing Nintendo and Sony how they were 5, 10, o 15 years ago, because Nintendo had the upper hand easily, we are talking in 2018 and inmediate future . Nintendo have Mario 2D and 3D, Pokemon, Zelda, Smash, Mario Kart, Animal Crossing, Mario Party, Splatoon, Donkey Kong Country as huge sellers and Sony have TLOU, Uncharted, God of War, Horizon, Gran Turismo, Spiderman and most probably (but if you don't want to count them i'm fine) Ghosts of Tsushima and Days Gone. Look, I'm not saying Sony surpassed Nintendo by any means, I'm still think Nintendo is the bigger software company in the world, but now Sony is closing the gap, and they can be actually compared as this topic is a proof of it.
By reaching "Nintendo levels" is just to say, that Sony now have more than 5 franchises that can be compared to the biggest franchises in terms of sales, nothing more, nothing less, but yeah, Nintendo is still number one.