This will demonstrate that OPFOR clothing has armor, whereas other faction's clothing does not.

1. Start a Zeus mission (This is necessary because the Virtual Arsenal level, accessible by the main menu, does not put clothing on the VR entities)
2. Play as Zeus and begin the mission.
3. Place down three units.
4. Use the Virtual Arsenal module to adjust one unit's loadout.
5. Adjust their loadout and remove all equipment except for OPFOR clothing {example: "Fatigues (Hex) [OPFOR]"}. Observe in bottom right of the VA UI it lists "Armor" as an empty bar (0).
6. Adjust the next Unit's loadout to have no equipment, except for a generic piece of clothing {example: "Combat Fatigues (MTP)"}

7.Adjust the third and final unit's loadout to have a low-impact weapon, such as the PDW-2000 9MM.

8. Use the Remote Control module on the PDW-2000 unit.
9. Fire a round into the Combat Fatigues unit's chest. Take care to hit only the torso. Observe the unit die in one shot.
10. Fire one round at a time into the OPFOR-clothing unit's chest. Observe it takes 3 shots to kill the unit wearing the OPFOR clothing.

Note that OPFOR clothing is heavier to compensate for the additional armor. This is not a matter of imbalance, only a matter of bugged UI.

Presumably, clothing added by community mods that gives armor also would not display properly in the Virtual Arsenal UI, though I cannot confirm this.