[Mobhack]

If A is selected as the spotter and plots battery A's fire then battery A is spotted by A.

If B is then used as the spotter and plots battery B, battery B has observer B as the spotter.

If you select observer C and use him to move battery A or B's impact - then C takes over from the previous spotter, whoever he was.

The battery has a record of who his spotter is. Using a new one to plot or adjust changes that, naturally.