I really can't say. Must have been the notion that the War Machine armor was a specialty armor on par with the Hulk and Thorbuster in terms of power so it was grouped with them. However, that still contradicts the chronological order of their appearances, as War Machine was made long before the Modular and the Renaissance armor. There's just no rhyme nor reason to it. Just think of your War Machine status as being like the Parnell Jacobs model that Sunset Bain's lackey upgraded. That one seemed to do a good job kicking Renaissance Armor Iron Man's ass.