In order to answer your question, i'm working in the Danish Defence, as a seargent for recruits who joins the army at the age of 18, and we undergo training based on the danish standards within a limited time, in regards to the game here, i've been told it's based on a military Sandbox, which contains the ideas of military warfare.
I can relate to the part with running around with backpacks, throwing smoke grenades, combat stances etc etc, but all in all, i think it depends on where you're from, we train to figth in the dark and from the woods, aswell with the situation in Afghanistan, we also train by figthing in compounds and looking for IED's.
I'll be honest and say it's hard to say if we can relate to the game, since this is an RP server that i've dedicated my last 4-5 years on, and i can already tell you now, i've never driven a quadbike, or getting deployed in a prowler/quillin from a VTOL.
If you got any specific areas you think is relateable, ask away and i'll do my best to put a clear view on it.