The only undertracked sales are for the DS.
Both others are not undertracked at all.
Look at the 40m Wii software difference. There are ~3000 Wii games and that would mean that every games has under 15k units available in stores around the world (and online obviously).
That's not much, considering that popular games such as several Marios and Just Dance games have a stock of 100k each.
Also some European sales for older Wii games (and 360 games) have been lost (at least temporarily) so the true difference would be even smaller than 40m.








