No mention of the race or ethnicity of the two soldiers and the driver. Might not mean anything nor matter if we did know, but then again it might. Also not mentioned is what kind of guns, rifles, submachine guns, or pistols, the troops had. If handguns, according to the NRA/ILA site, NC is a shall issue CHL state, so LEOs should be ready to encounter civilians legally carrying a handgun, however "THE PERMIT HOLDER ... IS REQUIRED BY LAW TO DISCLOSE TO ANY LAW ENFORCEMENT OFFICER WHO ADDRESSES OR APPROACHES THE PERMIT HOLDER THAT HE IS A PERMIT HOLDER AND IS CARRYING A CONCEALED HANDGUN, something the soldiers may not have known and/or may not have done. (Not that the law, if it's like those in other states I've checked into, probably applies to federal military acting in a duty status.)
This is the sort of thing that happens when carrying a firearm becomes uncommon and a cause for instant suspicion and alarm. A fact acknowledged by the very requirement of the NC CHL law requiring notification of any LEO approaching, whatever that might mean, a permitee.
None of your concerns are legimitate concerns for that area. Not only is there now a HEAVY concetration of Mexicans to the point where half the main town has Mexican owners,but there have been blacks operating there with the teams since the 1950's with no problems at all.
As for the firearms concerns,this may be the only place I know where you can drive through town with a sandbagged M-60 across the cab of your pickup,and have people smile and wave at you.