I just watched a movie called #Terminator2. Perhaps you've heard of it? Well, I read an interesting theory not too long ago in regards to people nitpicking that T2 shouldn't exist based on the events of the first movie, particularly Reese's line about them sending, "just him... and me".

When T2 starts, that idea is thrown out the window when Sarah says Skynet sent back two terminators. One could argue why they didn't send the T-1000 back to kill Sarah when she would be less prepared for it. The solution to this dilemma was actually pretty simple. Most people assume they were sent back in the order of the films: The T1 characters sent first, then the T2 characters. It actually makes sense to think of it the other way around.

Skynet sent back their best prototype to kill John directly, so Tech-Com sends back the best bet against it, a reprogrammed T-800. Then, Skynet has nothing better than a T-800, so they try sending that after Sarah as insurance, and Tech-Com has no time to set up another T-800, so they send back Reese. That could explain him not knowing about Uncle Bob.