I don't really dig the pose much. Right arm forward with right leg forward isn't a natural way to move. And having his left arm coming forward too, looks like a very robotic way to stand.
You might find it helpful to actually try and strike the same pose, and see where your left arm feels comfortable and balanced.
My suggestion would be to swing his left arm outward and slightly back. As if he were holding his shield up to protect his face from imaginary arrows. I think that would balance out his shooting arm more.
Perhaps not unlike the original Calgar figure. His arm doesn't need to be right up in the air like this, but I think a bit higher and wider would be good. And I'd have his eyes staring right in the direction he is shooting. Helmets are meh... I personally get a bit fed up of looking at those same old
BA heads over and over. But I tend to think the spiked halo helmet and wreath helmet are the most authoritative looking ones. The champion style helmet is really cool, but it doesn't feel to me like something a Captain would ware.