For a long time, Shigeru Miyamoto, Nintendo's star player, lead the company's largest division, Nintendo Entertainment Analysis & Development, or Nintendo EAD as its often referred to. The division was responsible for nearly all of Nintendo's flagship cash-cows such as Mario, and Zelda, and green-lit the creation of newer hits like Animal Crossing, Pikmin, Nintendogs, and Splatoon. Miyamoto touched nearly all of EAD's work as either Producer, and later General Producer.
Meanwhile, a much smaller software department in Nintendo, Software Planning & Development, or Nintendo SPD, was created and led initially by the late Satoru Iwata in 2003 and eventually led by Shinya Takahashi in 2010. This division specialized in both small-scale, innovative games with less development time, and a smaller budget like WarioWare and Brain Age, as well as overseeing externally developed games produced by the company such as the Fire Emblem series from Intelligent Systems, and Pokemon from Game Freak, with management that was safely out of the hands of Miyamoto-san.
In 2015, these two divisions, merged following Iwata's passing. Now all of Nintendo's games internal or otherwise, are ran through the Entertainment Planning & Development Division, or Nintendo EPD. Unlike EAD, Mr. Takahashi from SPD is the man in charge, with Miyamoto taking a higher-level, more hands-off position as a company wide creative consultant. It's been about 4 years since the merger now, and I'd like to ask, based on interviews and games released when these two were managing their respective divisions, what differences do you notice between them? In my opinion, in terms of producing and management style, Miyamoto always seemed like a Micro-manager. You have interviews and reports of him coming in and insisting changes to things to make them better. Takahashi meanwhile, seems more laid back. He helps give guidance and discipline to the developers when needed, but for the most part, he kind of lets them do whatever they want to make a great game.
Another difference is in the games that get made. Miyamoto likes making games, but he also liked making Mascots. Family-Friendly, easily marketable characters that can resonate with as wide of a demographic as possible. He always looked to Nintendo's established roster of characters to put into a new game concept so that people can play something new with a familiar face. A big example of this was with Star Fox Adventures, It originally started out a completely different game named Dinosaur Planet for the N64, meant to be Rare's swansong for the system, but then Miyamoto came in and insisted that the team rework it into a Star Fox game for the GameCube. Takahashi is a bit more liberal that that it seems. He doesn't seem to force developers to use established Nintendo characters if they can, but if that's what they want to do, then he could easily arrange that.
There's another difference regarding the two, and that's the willingness to co-develop with external developers. Takahashi's always had a lot of ties with different studios, and with EPD, he's willing to bring in external developers to help direct in-house creations like Sushi Striker or Wii Play Motion, the latter of which was developed by a ton of different studios. Miyamoto dabbled in this a little bit, when making games like Star Fox, but he always preferred to work with people within the company whenever possible.
But the biggest difference is the philosophy regarding target audiences. Miyamoto always seemed to prefer targeting a wide audience with one single game. Forgoing difficulty settings and niche titles, in favor of a game that can work on multiple levels. He's played a big part in Nintendo cultivating its Family-Friendly appeal. Meanwhile, Takahashi also believes in casting a wide net, but he seems to do it through a diverse lineup of software rather than multiple games that work for everyone. He's stated in an interview that believes each game should have its own mission, and if it does it well, then its a hit. This is possibly why you see Nintendo internally in recent years, taking a chance on niche, slightly more complex projects like ARMS and Nintendo Labo. Titles that don't have as much universal appeal as Wii Sports or Mario, but still do a good job at reaching their desired target audience none the less.
TL;DR - In terms of management style regarding producing games, Miyamoto was always hands-on and involved, having say on how a game should look and feel for maximum sales potential, while Takahashi plays more of a supporting role, letting the developers do what they want, so long as it serves the game and its target audience.