Yeah it is, I just noticed it, his shoulders need to be broader and then the shoulder pads of the armour need to be made bigger to compensate the new size.
Here is a comparison:
And here is one after the image of your model has been resized.
His torso needs to be bigger, his head needs to be longer (not bigger, not stretched so it gets thinner, just longer). And stick the chest out more. Also the place where the yellow shoulder pad meets the blue chestplate (the seam) needs to be lowered.