I don't put ammo high on the list.
Sure I want the most realistic thing possible, but I want this game to be successful first.
You have to be real careful trying to put "realism" into every aspect of a game. First you might actually break the game (as in the case with the AI) by over complicating things. Second - you might turn off gamers who just find the game learning curve far too cumbersome.
I've seen it with recent games like DayZ. I pull out my compass to see which way I'm going. Oh, wait... first I have to pull it out, then I have to raise it up, then open it. Same with a bottle of water. Click to put the water in my hand, click to open the water, click to drink it, click to put the cap back on, click to put the water down, click to put the water away.... just way too much.. but there are people who scream for realism. I just think you have to be careful when you get into these aspects of the game.