Your number still dont add up.
Dec 10 is over 10 million, we agree on that.
Then you say 2.5 million over the next 2 weeks.
That brings it up to 12.5 million with one week left in the year.
That final week will still be a few 100k, so ~12.8m
Then you go on to say 12.3 million sounds right.
thats if we use the highest number, remember using NPD data, 1.5 million for all of December right, we get 800-900k after the 10th from using basic estimates, since npd track from the 26 cyber monday included, we know japan is around 650k, we also know north america is nintedo best region so 600-700k for Europe the numbers are very close.