If you compare them without aligning FYs then you'll have to remember always that these quarters will cause a big movement to one side or another because their Holiday season quarter (were a huge chunk of the yearly sales are made) aren't aligned.
The reason of 3DS and WiiU not selling at launch went beyond the launch titles.
Same goes with Switch great success, it has more to do with combining both Nintendo markets being a hybrid, better branding/marketing to differientiate it from the previous product, better perceived launch pricing, now getting the handheld monopoly and so on. There are several examples of Switch games being crossgen/WiiU to Switch ports/WiiU sequels that are basically the same game that had great sales on Switch while tanked on WiiU.
Regarding the launch timing yes, they decided to avoid being aligned with the other ones. They have their own cycle and seems it benefited Switch to have their peak while the others are in an intergenerational transition with a generation dying and the other one starting and supply constrained, so are in their lower sales portion of their life cycle.