I may be way off base as I so often am but what I think "Drone" is referring to is that the rebels appear a turn before anything really happens. Generally, when an army is in a province and are besieging the city , they own it but this isn't true right off with the rebels. You can build new buildings or destroy old ones, etc and react by moving in more troops prior to the rebellion. If I understood you correctly, you are simply moving out your troops while you still own it thus allowing loyalists to form up the same turn the rebellion actually begins (at the end of the turn they appear).