Has anyone looked at the math behind building fighters in shipyards, rather than fighter factories?
I started my analysis on the assumption that you have a 1000 ton, 20 slipway shipyard. At an equivalent invest in research of 20,000RP, you get 1000 BP per slipway * an efficiency of 0.6 for a 1000 ton slipway (BP for a Naval shipyard is = 1+(((tonnage/5000)-1)/2)) or 20BP per fighter factory. Hence your 20 slipways produce 600 BP each for a total of 12,000 BP, which divided by 20BP per fighter factory means you need 600 fighter factories to achieve the same BP.
600 fighter factories requires 50k*1000=30M pop to work them. One 1000ton shipyard with 20 slipways requires 1M+100*(total tonnage of 20,000)=3M pop to run the shipyard. That's a HUGE benefit early game when pop tends to be a limiting factor
600 fighter factories requires 120 Vendarite each for a total of 72k Vendarite. One 1000ton shipyard costs 1200 Duranium and 1200 Neutronium, plus as far as I can tell about 100 D and 100 N for each slipway, for a total of 3200 D and 3200 N.
So by the numbers, a 1000ton shipyard with 20 slipways is strictly superior in population cost and mineral cost to the number of fighter factories required to achieve an equivalent BP, at the same research level. Not to mention that shipyard BP per research scales up faster than fighter factory BP per research. The ratio of Shipyard BP to fighter factory goes from 40 at start to 80 at the end of the research chain. Further, that 1000ton shipyard can also be used to build FACs for boarding or other purposes, and if you avoid fighter factories all together in favor of shipyards, you can skip researching Fighter Factory BP tech, whereas you will always need the Shipyard BP tech either way.
My conclusion is that there is no reason to build fighter factories, ever. Did I make a math error somewhere, or a bad assumption, that makes fighter factories more useful than they appear?
Update: I originally neglected the fact that the build rate is standardized on a shipyard of 5000 tons. A 1000 ton slipway, the smallest you can build a new shipyard, only gets 0.6 times the BP.