And the other thing I'd like to mention is when Ellie finds me ammo and I have to restart the checkpoint or die in battle. Why doesn't she find the supplies a second time? Isn't respawning or restarting a checkpoint like the same as taking a step back in time? I'll get six shotgun shells, restart or die, and then not get anything from her. Another unrealistic aspect.
I don't think it's random. I got health packs from Ellie or Tess when I needed one, didn't have one, and didn't have supplies to make one. As long as I was able to make a health pack, nobody gave me one.
Same with ammo. I never found ammo on my stealth kills. I played mostly stealth so ammo was very hard to come by, but then again, I didn't use it either. I only received ammo from Ellie early in the game. After that I only found it on rare occasions. By the end of the game I was full up on shotgun, rifle, and revolver. I had enough whenever I needed it, but not a lot. I've seen youtube videos of others finding lots more ammo, but they were shooting more too.
I played Hard to unlock Survivor, then I only play Survivor. I think the game is well balanced and adapts to how you play so that it's not easy or comfortable, but super tense and survivable; barely. I've been thinking of trying a run on minimum supplies to see how that goes. I've also wondered if I would find more shiv parts if I used shivs more frequently. I'd say there is plenty of replay value here.
I agree with the kneeling and rifle the body for ammo, if they got a gun, at least one or two rounds off the body, maybe a bar of chocolate or a tin of peaches, I find the randomness quite good and realistic whether Ellie gives you anything, sometimes she will find a couple rounds for "El Diablo" and on occasions, she will pass you a more than welcome health pack, in fact, on survivor mode, i never craft them unless in an extreme emergency, it's molotovs all the way, and Ellie can be quite usefull.
Also sometimes she will leap onto a guy when you're getting a good slapping, or shoot, or throw a brick, the AI in the game i find varies from game to game, sometimes it's hilariously funny, like the guy who watched me strangle his mate as he nonchalantly walked past, to some really good AI encounters.