2 problems: Animal crossing new leaf is not labelled as an 3DS game ( already reported it) + many GB and GBA Super Mario titles are tracked twice: super Mario Bros (GB) & Super Mario Bros Deluxe and so on.
additionally there is a 2nd entry for new super Mario Bros 2 on 3ds with just under 1 million copies.
The last one: There is an entry for Friend Collection: New Life on 3Ds but the game is called Tomodachi life in the west and gets already tracked separately