Next, the tank was clearly a mock-up, it did a poor job of looking like an Abrams, and the inside was entirely too spacious. They also do not have escape hatches on the bottom since that would make it more vulnerable to mines.
Even with out an escape hatch a tank is extremely vulnerable to a mine going off beneath it.
The weakest part of the tank is the bottom and then followed by the top (which is why we have weapons to attack tanks from the top). Your armor is concentrated on the front, back, and sides.
If the bottom was as strong as the sides of the tank you'd have a tank that was too heavy to move.
Finally, will the survivors be smart enough to use suppressed and silenced weapons later on in the series? Heck, even bows and crossbows would work.
Judging by the comic books........