Here is a still I grabbed from a video where they've used a pose very similar to mine.
You can see how the pauldron (or lack thereof) exposes the pad underneath on the shoulder, since you can't put a big curved surface onto the relatively-flat area you get with this pose.
The pauldrons for the sergeant have some stuff hanging off them, which makes the problem even worse - you can't get it straight on the arm because the extra bits dig into the arm.
Does it matter? Are yours all like this too? Want to make sure I'm not a fethwit.
I can get it decently on there, but then there's a massive gap on the rear side like in this other photo I found. Not sure what's best here - if I want to focus on covering the pad, or on getting the pauldron to fit around the back.
(Apologies if this isn't the right forum section - I figured it was a "modeling" question)