I'm not sure that is a fair comparison because of the huge difference in installed base, it was rather easy to sell 1m on PS2 compared to Xbox because only like 1% people had to bought it, basically that list is only good for seeing what larger installer base provides and how important that is to the publishers. Ninja Gaiden must be really close to 1million, but it's hard to find sales numbers, the original sold over 600k in US and if you factor in Black it's surely over 1mil worldwide.
To me, the list really illustrates that the "system sellers" for the most part, aren't really going anywhere. Meanwhile there's alot of talk about just that sort of thing. MGS on XBox. FF and DMC on Xbox. Just alot of unsubtantiated stuff. And the reasoning behind it is sounds, but look at the list and sure enough, alot of those franchises are pretty much stuck on Playstation.
Of course, the XBox ones seem just as stuck but I haven't been getting "the message" that games are going the other way, despite the PS3's dramatic increase in PC ports compared to PS2.