So real in fact that, for a game, it was overkill. A happy medium does have to be found. It's mostly up to the developers, but they don't have a large margin to work with. The physics have to be real enough to be believable and simple enough to be intuitive. Digging Out of the Muck Other parts of the game are easily muddled.
Weapons are a tough decision for any development group.
However, they shouldn't be unintuitive. It should be easy to grasp each weapon's use and effectiveness. It's just one more thing to learn to use. Balancing weapons and the amount of weapons are things that usually go hand in hand. A relatively low weapon count makes it easier to balance weapons.