So, I think there is something slightly interesting here. War is meant to embody a part of us, as a whole (at least that is what was presented to me), the beastly, angry, warlike side. if you notice, his personality is focused, somewhat barbaric, yet highly skilled. His personality is reflected by the seemingly random nature of his weapons and armor.
War embodies a few things.
1. Fear, monster faces, and gruesome appearances.
2. Anger,
3. Brute Strength, Note the shear size of his left hand
4. Mental Strength, Note the symbol on his head, this portion of the skull is called the Mental I believe
5. Strength of Will, Note his unchanging facial expression, eyes that lack any form of amusement, constant looks of disdain. It shows a focus and intent.
6. Brutality, This one is found in almost every aspect of his character design. He is large (looks to be about 9+ feet tall), His armor is all crude yet effective.
Maybe I am the only person who sees these things. The thing is, I can see the reason why they had this level of character design. War is not Human, so he doesn't need human proportions. If you believe it to be a lack of ability in the design team to create proper human models, look at the Wretched (Undead people) and the initial cutscene which show humans with natural proportions. War is not human (I can't stress this enough), and it is clear that it wasn't an oversight, so much as a design choice to have him have differing proportions.
When you look at war, as if he really existed, what do you see? You see white hair, indicating age, but you don't see wrinkles or other signs of age, so perhaps he is simply mentally aged (wise) as is accepted in some cultures. You see brutal armor which all reflects anger, brutality, and fear. War is the aspect of War, he will embody that in his character design.
War is complex, so is War (You can read tat any way you want).
With that being said. I have no doubt that some parts of the armor and demeanor were added because "It just looked cool". But in the end, even that stems from some creative process. So, maybe he could have been designed better, but I believe he fits his place. He is supposed to stand out, he embodies war, it is his purpose. Why would he, in his brutal killing perfection, blend into the background?