Soundwave on 16 August 2017
Wii hit a brick wall in Japan by about year 3 and the fad fizzled out, so that one probably isn't the best comparison. If Switch only sells as well as the Wii in Japan that will be a fairly large disappointment. PSP outsold the Wii in Japan.
DS ... is a tough one because it turned into a phenomenon in Japan by capitalizing on touch screen games before the smartphone took over that completely. Don't think Switch has that level of appeal, it's a more traditional game system for its time.
3DS is a reasonable target for the Switch in Japan, but 3DS is still pretty tough. While maybe somewhat of a dissapointment in US/Europe relative to Nintendo's past handhelds, 3DS did very well in Japan.
