Interesting that armour plating might be a thing again. The Germans have kevlar panels that they can install in some places inside their ships (magazines and such). With modern armour technology there are likely some very interesting options.
As far as crews, the US and French have both remarked that crew sizes need to be large. The French in particular stated that they bet on smaller crews and the Red Sea showed them that they bet wrong. Mainly because of exhaustion while being on station for long periods of time.
So what this tells me is that to counter drones ships might get bigger and heavier, to carry the armour and have more crew. Thats an interesting thought experiment.
Less WW2 armour plating, and more having some kind of blast resistance and a standoff from the hull. That's where the discussion came up to the old WW2 torpedo nets (basically weighted steel nets on trawler arms) to get a standoff distance for things like the zodiacs and RIBs turned into remote controlled IEDs. Hull plating in general is pretty thin overall, but even thinner on the superstructure, so things like having some blast shield panels with an open space before the actual superstructure (and probably something like kevlar to absorb the shrapnel) built in. So basically sacrificial structure to take the hit, disperse the shock wave, and be easy to replace.
Starts adding a lot of top weight but still far less than the old 1"-4" or armour plate they used to have. Would do SFA against actual missiles, things like RPG or other significant munitions, but good for FP against boats or swarms of small commercial type drones strapped with a grenade.
That could all be retrofitted to a lot of the existing ships, but not so much newer ships that have everything covered for reduced RCS, but was just a bunch of survivability/recoverability nerds (that are familiar with ship design and maintenance) kicking around some ideas over beers and coffee.
The small drones are pretty hard to pick up apparently, but shotguns with bird shot is a cheap and easy way to take them out, and generally things are calm so lot easier for people that have practiced skeet shooting from the ships to aim in on them. But they don't look as cool as whatever NTOG 2.0 picked up so whatever, and I guess you can always have a few guys with the long barreled shotguns backing up the 80s Robocop fancy weapon.