Somebody said in this thread that he routinely builds one farm per 3-5 factories. My own research indicates it's wiser to build just one factory as the first building, either next to the capitol or on a manufacturing bonus tile. Then I never build any more factories. On a big planet I'll have one hospital and as many farms as possible.
For the last two weeks I've been playing on an excessive map. I'm now up to turn 360 and I have 125 planets, having conquered half the map. Now I'm going after the very built-up Dreadlords. I've never built more than one factory per planet, I've never had money problems at all (I keep the main slider in the NE quadrant all the time), and I'm crushing the 18 AIs in every category. (I'm playing a "normal" map; time to move up.)
I'd suggest taking two planets of the same size and trying the all-farms approach on one, the mostly factories approach on the other. You may be surprised.
I'm very glad they did away with the production wheel for each planet. With 125 planets, that would just be impossible to manage.
Now my main hope is that they'll add a set-up option so that you can play with a limit of one economic starbase per planet, if you wish. In my current game I have more than 200 starbases, most almost completely built up. That's too much work.
All farms+approval isn't always the best strategy, but now that the wheel is gone, it's pretty close.
Say you're running 33% flat global wheel, with focuses. Here's the output of a planet with 10 population, set to manu:
manu: 8.7
research: 3.15
Econ: 3.15
Total: 15
Now, if we build a factory, here's the output:
manu: 10
research: 3.15
Econ: 3.15
Total: 16.3
Here's what we get from adding a farm instead:
manu: 9.86
research: 3.5
econ: 3.5
total: 17
Here's the results at 20 population:
m:14.5
r: 5.25
e: 5.25
total: 25
+factory
m: 16.67
r: 5.25
e: 5.25
total: 27.17
+farm
m: 15.66
r: 5.67
e: 5.67
total: 27
This is about the point where the factory starts to overtake the output from the farms. But 20 population, in the early game, means you need to build and populate 8 farms before the factories become a better investment; even if we account for approval, there is no reason to build any production buildings on a planet until you have 4 farms and 4 morale buildings. Every factory you then build increases the relative value of another farm.
The best build queue is therefore somethng like:
farm
farm
farm
morale
morale
farm
morale
morale
factory
farm
morale
factory
Substitute 'factory' for research labs on research planets, and for econ buildings on econ planets. You also have the added benefit that your population is vastly more flexible than a brick-and-mortar economy.
It would be quite cool if SD managed to balance it so an agrarian empire with highly flexible production output and few manu/res/econ bonuses was an equal option to a bricks-n-mortar economy that had basically fixed manu/res/econ values determined by it's buildings - so if the Krynn, say, had no manu/res/econ buildings but just lots of pop cap increases to give them complete production flexibility but very poor specialization, while the Yor had fixed, flat manu/res/econ bonuses from their buildings but no means to multiply their production value or increase their pop cap.
