Unlike Sony and Microsoft, Nintendo has never historically been one for big game studio buyouts. With a few exceptions, company execs like the late Satoru Iwata expressed that the problem with that approach is that you can buy the building and the name, but you don't buy the talent or culture that makes that studio special. The company has instead preferred the "Keiretsu" or Second-party model, where they would invest in or form strong exclusive relationships with independent development studios to create first party content outside of Nintendo's own internal game staff.
Companies like Intelligent Systems, HAL Laboratory, Game Freak, Grezzo, Good-Feel, Skip, indieszero, Camelot. None of these are Nintendo subsidiaries, but are generally considered "Nintendo studios" since they've developed almost exclusively on Nintendo platforms and the majority of their releases were published and co-developed by the Big N itself. Many of Nintendo's biggest or most beloved IP even came out of this model including Kirby, Pokemon, Fire Emblem, Golden Sun, etc.
However, Nintendo is beefing up its game development capabilities to maintain a steady stream of games. Meanwhile, Sony has been seeking out start up studios such as Firewalk and Deviation games to co-develop PS5 exclusives with PlayStation Studios. So should Nintendo EPD do the same? Seeking out start up studios that could be potential "Keiretsu" partners in both Japan and abroad to help their expansions? It'd be great if EPD can find and raise a new generation of "second parties" along the likes of Intelligent Systems, Grezzo, or HAL Laboratory. Platinum Games seems to be the biggest candidate at the moment, and I think Nintendo's been doing a decent job working with western partners like SFB, Velan, and Mercury Steam. But I think they could be a bit more pro-active at the moment. Maybe find some of the scraps leftover from JAPAN Studio, there's gotta a bunch of people who want to start their own studio.