When JKCK is in dual wield stance you can use JMLs special ability to call assist and he'll still get his bonus turn/second move. Only works in dual wield and not double bladed stance.
And regarding Nego vs. Exec - in my case they always seem to attack Anakin. Perhaps you shouldnt heal him right away because they attack the one with the lowest health and there is no risk of loosing him. Heal him after XB and RC first move.