I think the whole point of the Terminator
films is those paradoxes. Unlike in the Back to the Future
films, where temporal changes are immediately resolved, the Terminator
films are based around the twin facts that the good and bad guys both rely on time paradoxes
Both were created as a result of a war in the future which they come back to stop from ever happening, thus meaning they would never exist...... To stop the war which would therefore happen and they'd be... etc.
All a bit weird I know, but I think it's pretty obviously deliberate that these issues aren't addressed.