His arms might be a bit short. If you're using 8 heads proportions, the space from the shoulder to the elbow (precisely, from the acromion of the scapula to the olecranon of the ulna) should be about 1.5 heads, and the space from the elbow to the wrist (i.e. the ulna itself) should be about 1.25 heads.
Good stuf bro, keep it up. Is this made in dynamesh mode or are you sculpting on a basemesh?
Thanks, I am sculpting on a basemesh. And I wouldn't say his arms are short, but yes in render looks like they are short, it's really just because of the odd perspective angles that zbrush gives. Arms are a bit bent, so yeah that really gives the feeling of shorter arms. I've used skeleton reference as well before making base mesh.