let me break this to you, Arma is a bit away from being a Mil Sim
From all FPS games out there that could be at least vaguely comparable, BI tries to get closest to a sim of all.
When i follow patchnotes from other games, i see this:
while at BI i see thisweapon configs adjusted for balancing
This tells me something about what BI tries to achieve. While they might have a eye on PvP, their main goal remains to be authentic. If they succeed or fail is another topic.weapon configs adjusted to be closer to realistic behaviour
And i really, really dislike it to see other shooters taken as reference to compare ArmA with. Even more since i've watched a BF3 vid on YT where a player got into a vertical climb in a fighter plane, then jumps out of cockpit (still in climb), turns around and shoot the enemy plane behind him with his rifle and then get back into the cockpit and continue his flight. At this point i felt off my chair, LMFAO and closed the vid, asking myself how people can play such a crap.
So, ArmA might fall a little short as a sim compared to DCS products or other flight sims, but it is lightyears ahead of any other FPS actually available.