Not sure I agree with your reasoning.
I can think of several cities with major military bases, and a hell of a lot of manpower and material handy. Not being an Angelino, I have no idea what they have there, and am simply assuming they’re busy elsewhere, having pacified this particular suburb with maximum prejudice.
But it’s also implied that the center isn’t holding. We get to hear as one squad gets taken apart, over the radio, which indicates that things are nowhere near as stable or as safe as the Lieutenant is saying. I’m ASSUMING that our soldiers have been made responsible for a particular piece of map, and that they are gradually losing ground, partly because of a hell of a lot of zombies, and perhaps due to the Lieutenant’s idiocy. I’m just irritated that I have to assume this.
We got a lot of visual clues about what happened in the Atlanta area. We know why there were no zombies wandering around Rick’s hospital, and we spent several episodes looking at the incredible traffic jam leading out of Atlanta. The clues were in the actual plot, or just lying there for us to see. THIS time, though, they seem to be going out of their way to leave us as clueless as the people in the show. WE knew what was in the cafeteria in the hospital, and we knew why there were body bags piled up in the loading dock. The point being, RICK was shocked and horrified and scared, while we sit there and eat popcorn and go, “Yup, you’re in it now, Rick. And we will be with you while you figure out WTH.”
As opposed to simply sitting there as the popcorn grows cold, every bit as mystified as the characters in the show.
As far as the military goes, I am led to think of the First Battle Of Yonkers in the book World War Z. It’s told as a flashback, by a survivor, a soldier who was assigned to keep the seething masses of zombies from moving out of their location… literally, millions of them.
They tried setting them on fire. Bad move. Fire will eventually kill a zombie, maybe, but not quickly enough to keep him from getting to you.
They tried massed assault weapons fire. Didn’t work. Takes a lot of firepower to render a zombie harmless if you don’t get the head, and it’s wasteful of ammo. And while you’re reloading, another million zombies is slogging forward.
They tried antipersonnel weapons, cluster bombs, grenades. Didn’t work. Even if you shred his legs, he can still crawl.
And finally, one guy snapped and began freaking out… on an open mike circuit. Panic spread through the ranks.
And the zombies won. And this is in a situation where they knew exactly where they were, where the rear lines were, with the best equipment the US Army could muster, and they even knew where to shoot a zombie to kill him…
…and this is where author Max Brooks thought it out a little better than our showrunners have. Where are four million zombies? We know they’re attracted to noise, and the army’s the noisiest thing going now. Oh, and killing civilians who are in no position to stop you? Literally, just to cut down on the number of zombies? Seems like this would be a non-starter unless you can get them all to line up for a bolt to the head, and I find that unrealistic. Next week, I’m wondering if they’re just going to call all these people out, tell them to line up, and then open fire, or what?
…not to mention the effect on American soldiers, being ordered to shoot harmless people who’ve committed no crime…