Iron man 3 was made by an entirely new crew, director, and the props where all done by a new company. Those HoA displays and full display suits are irrelevant. The people from IM1 have stated they made the mk3 as a flight suit with limited fighting capability. The people from IM2 stated, even in the art of book if I recall, that the subsequent suits (4/6) where made larger, bulkier and for more space/comfort. Hot toys has the 3d digital files for all the suits. So the suit makers for the actually movies made it clear the first suits where purposely smaller and had less function and the people who made the figures have access to the actual blue prints for the suits...I’d say they made the figure based on that info and it’s accurate.