When it comes to games sales, particularly older games sales, VGC does not claim complete accuracy. However in the vast majority of cases its the best you'll find (for free)!
In this instance however it appears you have misunderstood the difference between shipped and sold to consumers. Tekken Tag may well have sold 1.3 million copies to stores. This site tracks how many copies have been sold to consumers. 200k sitting on shelves around the entire globe does not sound unreasonable.
It may have shipped 1.3 (1.5 as of the end of March last year) million copies in 2013 but it wouldn't have only have sold 1.1 million copies as of June 2014. So not only did they ship anymore copies out after March 2013 but there's also 400,000 copies out there on the shelf?
Naruto may have shipped 1 million copies across US and Europe by the end of the month it was released but it's only actually sold 1.1 million copies as of present?
No they're both well undertracked.