I would wear something easy to move around in...
Modern Military uniforms are light and very maneuverable. Plus wearing some kind of kevlar armor will prevent you from being shot / stabbed / hit, etc. Actually it wont PREVENT it per say, it will just make it non-lethal.
can it vary from person to person?
When that happens your a sloppy mess. A gaggle of dis-organized wanna be's. - NOT an army!
Keep in mind this was done on dA as a response to the flood of scantily clad female warriors of some future fantasy land. Blarrrrr its so unrealistic. I know fantasy isnt supposed to be, but - it seems kinda objectifying, to me at least. There is NO PRACTICAL REASON to go into combat almost naked. NONE WHATSOEVER. In real life that is.
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a long smile. hehe