I do think it likely there's a big difference in ability to respond to a crisis between "we have some capacity and expertise, but need more" and "we have no cap

I do think it likely there's a big difference in ability to respond to a crisis between "we have some capacity and expertise, but need more" and "we have no capacity or expertise, and need more", but admittedly I don't know how crucial having the right knowledge & existing systems/processes to copy, is for spinning up new shipyards. I would expect "copy this shipyard and have the experts there train others" would go a lot faster and have far better outcomes than "build a shipyard from scratch with no easily-accessible reference or expert trainers". That'd be the a big part of the argument for the value of preserving even a wildly insufficient level of manufacturing capability for certain vital goods, I'd expect—that is, it may not be necessary that the effect is to have a large and thriving shipbuilding industry, for it to still be worth it.