We should be able to set a priority queue for PD. I would imagine that in real life, in a US Carrier Group, the Arleigh Burkes would totally ignore their own defense if a sizeable number of missiles were headed for the carrier.
In VB6 missile salvos move in decreasing order of speed. Point defence operates as those salvos arrive at their targets. Ships with Final Fire will protect whoever is getting attacked, potentially sacrificing their own defence if a salvo attacking them is moving later in the phase. Ships can be set to Final Fire (self-only) to prevent that happening. Generally, this isn't a major issue because incoming salvos in the same wave are often concentrated on a single target. if multiple targets are attacked in the same wave, that leans fewer missiles per target, making it more likely ships can handle their own defence.
I can add some more options, but this can get complex
really fast. For example, if this is automated, will an Arleigh Burke shoot at one missile heading for the carrier or twenty missiles heading for it. If it would protect itself, what does the balance of missiles have to be before that equation changes? Does it depend on the performance of the missiles, or the existing damage to the CV or DD? How about what other escorts ships are doing? Do you even know which enemy missiles are heading for which target. If not, what do you do in that situation?
I am happy to implement any additional, straightforward point defence rules. It's just tricky to make them 'straightforward'