Possibly undertracked some 100-300k, even if not, 220M revenue day one is definitely sold rather than shipped.
quite likely. But even if it were shipped, it wouldn't be overshipping, in this period it's normal retailers build up supplies for BF and Xmas, and they know they'll sell quite more than 1st week shippings. If we just consider that for BF big chains will further improve the already wide Halo 4 choice with discounts, vouchers, special offers, unofficial bundles and other forms of added value...
Maybe it's not up to the highest Halo records, but this late in XB360 life it's doing very well, also at selling HW.