But, the cost per unit for FF modules is roughly 10 times that of most automobiles. And the 40,000 to 50,000 units per year is WAY above that of packaged equipment such as gas turbines, etc. that are individually made on a shop floor. Focus Fusion modules would also be much more standardized, with only a handful of variations needed (electrical or thermal output, possibly size of output, frequency (60 or 50 hz), etc).
Also, likely to be lesser number of factories. If each factory turned out one module per hour for 8700 hours per year, 5 or 6 factories would meet the US needs. This is similar to the production rate of aircraft in the US during World War 2 (about 100,000 per year, of all types, as I recall). Complexity wise, I would compare a FF module with a WWII bomber. That was an assembly line process, and they were large, technical items.
By the way, Ford made bombers during World War 2.
Then, after the “boom” years and demand fell off, the factories could cut back to a single shift, 40 hr week. That alone would reduce production to 1/4 of the 8700 hr/year figure, which requires 4 shifts of workers to achieve.