Had a rather interesting game as Catherine, I got a riverside start with I think 2 gold, and 1 silver, or something crazy like that, I built a mint there, and my capital was producing like 20 base hammers and something like 40 gold, in the BCs (this might have been during a golden age but believe me my gold income was CRAZY!)
Yep,I had those horses nearby too, and went for the republic policies for +1 hammer, should have gone perhaps towards tradition to help my relatively food poor capital, which didn't really grow after 6 pop.
I guess one of the "problems" is that you really need iron, in a habitable area with food, in order to get a good production city, because you need iron nearby to build a forge in the first place. In civ4 you had forges which enabled one engineer, and gave happiness for silver, gold, or gems, and a whopping, +25 hammers.
I wonder if the bonus from stables and forge stack together? (knights ftw!)