I like your work, im a big fan of the first Zaku. The zaku sniper though, seems alittle over damaged on the shoulder.
When it comes to gundam, I tend to get all... factuial, like the armor guys do with their tanks. A Zaku I sniper, as far as what it would have went up against, there is no enemy weapon that would make hits the size of the ones on the shoulder. The vulcans from the gundam would be to small, the Rifles (non beam) that the feddies had would be to large. (remember, there firing what amounts to be tank rounds, and a person is about half the size of that shoulder armor, Last, any ground fire from infintry would not be directed at the shoulder armor, it would be the legs or waist, to take it down.
Those are some of the things I think about when I damage my gundams. I actuially take the weapons and measure out the correct size of the blasts and cuts.
For things like beamsabers, remember, the slash would not normally hit center and end in the center, it would start from the edge and end center, or cut right through. If it would hit center, the damage indent would be alot less then furthur into the cut.