I go with MS has overshipped X360's for the simple reason to stay second in this generation so long as possible because sony passing them will create a negative backslash.
Sure I want to believe that X360 did better in whole of europe but it is coming from the same guys/girls who said how incredible the numbers are going to be in USA and who tried very hard to make people who dare to talk about adjustments look like a fool.
Never put your heart in Vgchartz numbers...