It’s a custom revisioning of the US aka Nato forces from arma 3, a combination of personal choice and current generation equivalents to the assets used by nato forces in arma 3, this one is designed to resemble a special operation specific soldier for example a recon unit as opposed to just being a basic soldier, no specific unit is represented but something along the line of marine force recon or an army equivalent

the timeline of arma 3 is 2035 as well so there aren’t definitive grounds for what something has to be as this is all speculative/custom