I have noticed that when I blow up all of the turrets and AA guns on my way to the command centre they do not re-spawn after I hack the command centre.
Also I have noticed that if I blow up the enemies defence command centre and then build my own defence command centre the layout of the turrets is different, this would be ok but I get less turrets!!
Is this something to do with the defence multiplier for multiple defence islands being next to each other?
If so is there a range limit? or if the next island is also defence (even though it is 2 to 3 hours away) it still gets this bonus?