I stayed in the Iron Age for about a year. I started with a couple of Blacksmiths (which I still use to complete quests that require you to finish a certain number of productions), goods and residential buildings and the Statue of Zeus. As soon as I got a larger number of WWs, I got rid of the residential buildings and built the ToB to keep my goods buildings running.
Then I got more WWs and some Sleigh Builders. Soon after, I deleted the ToB and all my goods buildings. I try to complete at least the first difficulty of the GE and the WWs produce enough current age goods, while Sleigh Builders produce the goods that are one age below mine.
A few months after that, I had more WWs in my inventory than I was able to place. I had reached the LMA continent map and my next expansion cost me 50k medals, so I decided to age up in order to get more expansions. I'm now in the HMA with 76 WWs.