Not to be a stickler, and knowing how well real-life comparisons are received by the "community", I have to nit-pick a bit.
The analogy of large-scale ship building in Sirius to assembly-line factory production of automobiles is a bit off.
To cut it to the quick, I'd be more inclined to agree with your arguments if the real-life comparison was instead to large-ship building, specifically military aircraft carriers.
These would make a much more palpable argument, but would in essence kill your argument as well, as one carrier can take 2-3 years to build (comparable to battleships).
Merchant ships, however, are cranked out much more quickly. During the height of WWII, merchant ships were being launched at the rate of 3-5 a day...from close to 25 shipyards. That's roughly one per week per shipyard (~6 days).
Sadly, I can't 100% agree with your argument in this case. Sorry.