Sure for Iron Monger and Hulk Buster... but for a rock monster? Preposterous!
i think thats supposed to be sarcastic... the Thing is still humanoid, as opposed to a 15' suit of armour, covered in extra parts, wires, etc.
Every time the Hulk fights the Thing they are drawn the same size. When Hulk fights the Hulkbuster they are drawn the same size. I may be drawing conclusions here but...