There should be no way for the normal zombies and I have not seen enough out of Ink and other smart ones to think it is possible.

When one breaks it down, it is a basic seige conducted by infantry in a resource-poor environment. Without seige equipment the zombies are stuck unless they can break with two dimensional thinking and go with the third. I do not see wings anytime soon, but sapping has a chance. There is more to it than just turtling behind a wall. But, it gets the basic down.

So, my guess is that Ft Irwin was instructed to Turtle or if they do collect recon intel, they do not care for the plight of what remains of humanity.

BUT, I hope the base did not turlte. It is a bad stratagem. One must have expanding zones of control. The further one goes from the base, the less control and retime time intel is required. At the base, we have the opposite where we have ever-increasing security and real time intel. Too many times this gets boiled down to "In Here" and "Out There". Afew undead run unti the wall and are ignored, The undead continue to attack the barrier and call for reinforcements. If one dams the trickling stream, a lake can form. The story-book version the dead are ignored until the wall is breached by a catastrophic failure.

The better policy is to setup zones of control and patrol them. At the redline were there is a transition from "in here and out there" must be cleared daily if necesary. It is critical to eliminate the randoms that arrive before the call for reinforcements. because the zombies also work based on zones of control. Although one may have a very small zone of control; arms length. With intel is limited to eye / smell, but the communication system is very advanced in its simplicity. Call for reinforcements and everything in 360degrees within in earshot is most likely on the move. In the their excitement, the ones within earshot can echo the call and extend the range frrom which reinforcements can be pulled.

Like Zapp says. The Army is always evil in the zombie apocolypse and I guess the commander will play the role of Burke in aliens. Smile and glad-hand while stabbing in the back.