It's a little telling that the writers for T3 and TS, Michael Ferris and John Brancato, but Brancato especially, only wrote those films because they were former dorm pals of Jonathan Mostow, but had no confidence in the project ("It felt safe, expected, paint-by-numbers"), did it for the wrong reasons ("Mike was building a house and really needed the money") and didn't even think the other films in the series were all that ("For all the cool digital morphs, [T2] was a sprawling mess, bloated and self-important. On multiple levels, it was a betrayal of the original. I couldn't stand it.")
Their original script for Salvation was, believe it or not, worse than the film. They had Skynet housed in some bubble where hybrids live in the kind of neighbourhoods you see in the opening shots of Blue Velvet and T600s tend to the lawns. Just bizarre.