Skynet is guarded by exactly one terminator without a gun.
Despite the fact that it is demonstrated that terminators can be created to exactly replicate the appearance and voice of people they’ve captured to infiltrate or lure the Resistance into traps, Skynet chooses to keep Kyle Reese alive to lure John Connor into a trap.
Seriously, what possible reason could Skynet have for keeping Reese alive? Killing him ensures that John is never conceived. Even if you’re willing to argue the grandfather paradox here, you have to admit, it couldn’t fucking hurt.
Apparently, you can jump into the ocean from a helicopter and just swim down and enter a nuclear submarine without any kind of diving gear.
The resistance has the talent and technology to perform a heart transplant.
The enormous ten-story tall Harvester robots are capable of astounding feats of ambush. They’re big, but they can walk on tippy-toes.
They also moo.
Blair is willing to betray her entire race and everyone who was willing to fight and die with her for a robot she’s known for less than two days and is unquestionably some kind of trap created by Skynet.
Terminators have highly-unstable nuclear power cells which would be much more effective as weapons against the Resistance than robots with guns.
These power cells apparently weren’t in the terminators destroyed in the first two movies.
John Connor is immune to radiation, because he’s usually within a few hundred yards of these nuclear explosions when they occur.
Skynet has no idea where the Resistance is, even though there’s a lake full of amphibious snake terminators in the lake two hundred yards outside their main base. Nor do these aquatic robots aid Skynet in any way to find the nuclear submarine serving as the Resistance HQ. In the ocean. The watery place you’d want your swimming robots to be.
Wouldn’t it have been simpler to simply stuff Marcus full of explosives and program him to explode when he encounters John?
John is a war hero among the Resistance for teaching them how to fight the machines and exposing all of their weaknesses like, uh, shooting them a lot and running away.