Post-apocalypse people shouldn't have needed dogs to spot terminators

The terminators are supposed to be infiltration units, right? Reese explicitly tells Sarah so. Her also says that unlike the previous generation, the new ones are hard to spot.

Really?

In the post apocalyptic world after judgement day, we see a shot of humans, dressed in rags, chasing down and catching rats to eat. This makes perfect sense in a world where people can hardly farm and raise livestock out in the open, but it means that people would be fighting starvation and malnutrition every bit as much as Skynet. And in this world you meet a freaking huge, musclebound stranger, and invite him back to your hideout, and you're not suspicious that this guy is so effing ginormous in a world where nobody else is getting enough to eat?

Cameron probably had terminators played by bodybuilders (the one that attacks Reese's camp in the flashforward scene was played by Arnold's best friend and fellow bodybuilder Franco Columbu), under the rationalization that they need to look like big men to disguise their massive, heavily armored robot chassis. But in a world where literally no one else could even possibly be eating enough and working out enough to look like that, it makes for rather a sizeable plot hole.