go have a look at the vid BFL had on their website recently. They had an identically laid out six assembly work benches, staffed by four people who would be sacked in my workplace if they worked that slowly.
The number of benches is fine, with pre-prepped cases and quick workers you can knock out plenty of rigs in quick time. We don't have masses of pre-orders, once they are done and dusted the farm machines will begin to roll out.
I'm not here to argue with you. If you are satisfied with what you see, everything's good. My point is a production line this is not, but if you're happy, i'm happy.