Should the cable adjuster be free to rotate relative to the outer?

I am trying to refit my cables and once the nut becomes captive, the motion of tightening the adjuster is tensioning the outer thereby making the throttle difficult to turn.
If it is not supposed to rotate, is there a way to tighten it without twisting the outer?
By their appearance, my cables could be original. Perhaps I have incorrectly identifed the cause of the stiff throttle?