According to VGChartz, Mario Maker and Yoshi's Woolly World on Wii U stand at 3.16m and 1.28m sold respectively.

Do you think the upcoming 3DS ports will sell less, more, or about the same as this?

I can't see any of them doing particularly well. I think both will sell less than their wiiU counterparts. I think smm will sell around 2m units on 3DS lifetime and Yoshi will do around 800k.

Both will be million sellers, Yoshi on 3ds may even sell around the same numbers as the wiiu version did, Mario Maker will sell more than Yoshi but way less than the wiiu version.

Mario Maker will reach the million, easily, but Yoshi is going to struggle to reach the 750.000 copies.

Mario Maker should do well with 1M+ but not as much as the Wii U version

Yoshi might get to 1M so it would be closer to Wii U numbers

Hyrule Warriors (460k 3DS - 1.26m WiiU) says hi. 1 mil for Mario Maker is likely, not much more. Yoshi miiiiiiiight be able to hit 600-750k, 1 mil unlikely

 If yoshi's woolly world was coming out late fall for Xmas, it have had a shot at surpassing the Wii U version, but in february, I think it has no chance.

Mario Maker won't be close to the Wii U sales at all.

3DS has a 60 million userbase and thanks to Pokemon Go, Nintendo is on the public's mind so both title should be able to reach a million. I actually think Yoshi will do better since that is a full game with additional features from the original. Even though Mario Maker has the Mario name, I think the gimped sharing feature will greatly affect it because that was an important feature for the Wii U version's success.

less simply due to the timing. the 3DS has been out too long, too late of a release. Otherwise they'd probably match the Wii U sales

Both will sell more than on Wii U