TIME has run an extensive interview with Arms producer Kosuke Yabuki and art director Masaaki Ishikawa and I would encourage you all to check it out. One of the things mentioned was that Arms and The Legend of Zelda: Breath of the Wild were made on the same floor at Nintendo. This allowed the developers to converse and use certain ideas that featured in The Legend of Zelda: Breath of Wild which the team found useful.
Arms and Breath of the Wild are made on the same floor at Nintendo, and we are able to use things that the Breath of the Wild team found useful. But it’s important for us to choose the right tools for the game. In development of this game, we looked a lot at the results of the battles, the overall picture of what character matches well with what character and what arms go up well against what arms. That information comes from humans fighting other humans. But we also use the artificial intelligence in the game to match A.I. against itself and look at that data. And of course the players who participated in the Armstest this last weekend, we looked at that to check and see if there are any balance issues.