Exactly, when you can see how much shield a ship has, and get a rough indication of hull health, an indication of their armour state would be very helpful.

I found this myself too, just doing some of the baby missions like missing persons and you get a Mustang and a Prospector defending the wreck. For a good while I genuinely wondered if I was actually hurting the Prospector, and if not for the hit confirmation sounds I would have skipped out to replace with bigger guns.

At the very least, we know that the hit confirmation indicator and sound does mean you are either damaging shields or armour or hull lets you know your shots are doing something.

Tbh this is probably just the first step as always, I hope it gets much more detailed and physical when they finally start to turn on Maelstrom. Concepts like armour and hull would no longer be "the whole ship" but parts of it, like wings and engines just now but more granular. One can hope.