Buying good developers don't guarantee good games, especially if the top creators/directors of such studios leave.
There are good professionals, talented people everywhere so what Nintendo should do is create new studios from the gound to make games in those genres that they don't have but need in order to succesfully compete: racing sims, Thrid and frist person shooters, among others.
Nintendo would be making the deals with those people, as that would be the point of getting the studios.
Nintendo would be making the deals with the owners of the studios. Not every studio is like Mystwalker, but even then, they can't be sure that the level designers, music composers, etc. leave.
That's the main reason why buying studios is not a good investment, you can end the the bosses and the "workers", but loose the people between the two groups, the perople that can turn a good/great developer shine or become just another studio.
Please excuse my bad English.
Currently gaming on a PC with an i5-4670k@stock (for now), 16Gb RAM 1600 MHz and a GTX 1070
Steam / Live / NNID : jonxiquet Add me if you want, but I'm a single player gamer.