The problem is that doesn't help me identify which specific countries/regions are undertracked, so while we can be pretty sure xxxxx game is undertracked overall, the question I then need to ask in order to make an adjustment is in which countries or regions and by how much? I can't just add phantom numbers to the overall to make up the numbers, I need some solid evidence of where I should be increasing the figures, and that will then filter into the overall figure.
@Poweranimals - Keep in mind the Nintendo figures include digital. But yes, some of them are undertracked (and iirc from when I last checked, one or two are also overtracked). They'll be adjusted as and when I get to them, while I'm going through each region making changes.
Thanks for the in-deph explanation! Obviously you can't just add sales willy-nilly, but it must be a touch frustrating to see a big discrepancy in tracking and not be able to adjust accordingly because you don't know where the sales went. I imagine it would help a lot if you found a way to reliably track digital.
As for Splatoon 2, the gap looks huge at first, leading to my impression that it must be undertracked, but it might not need big adjustments if it does have a high digital ratio.