Bob,
You may need a bigger boat!!!
C-3PO
It does look intensive as 10 boxes and 12 Arduino's. I will only need 4 relays of course.
A good job I am installing this in a 2.2M battleship, 30cm wide and 17cm hull depth.
The thought of wiring up the box internals is a little daunting, but the wiring between boxes is fairly minimal.
What we will have is each turret with its own fire control system, plus master and slave director controllers, and a digital compass. All operating from one Planet receiver. No wiring between hull halves, director control commands are transmitted independently to each turret with its own rotation arc/firing zones programmed in.
I have to say C-3PO this looks one awesome set up, and technically complex as it involves seven turrets.
Bob K