Nope those weeks were actually just rare exceptions. 3DS' second year had a pretty good flow of notable titles that boosted hardware sales. In Japan through the first 25 weeks of their second year, 3DS sold 2m (average 80k/week) versus Switch selling 1.1m (average 44k/week). Switch is still beating 3DS worldwide of course, but I would really like to see it do so in Japan aswell.
Thanks! Cause the Switch was doing below 40k. I guess the 3DS had that 40k- 50k baseline
3DS was much cheaper and had the XL edition released that summer, also.
Side note: Nintendo needs to stop playing games and announce a $299 MK8D bundle for the west and a Splatoon bundle for Japan. Bundles along with Smash and Pokemon for the holidays will give Switch a notable sales increase for its second year.