As I was updating my character's log I was thinking why didn't Zion install cannons in the tunnels with some video cameras so the moment they saw sentinels they could destroy them?
That's true. I was also thinking that if the cannon were in a certain location they would more easily find Zion's location (As though they even need the help).
That would be a wasted resource because for every sentinel it destroyed there would be a million more to replace it. What I actually find amusing is why they don't know where Zion is in the first place but that's another thread.