peter:
Something to think about. I just did a few Nomad Narrows games with Roman and Assy. When I "rushed" to Bronze both Civs were within 20 seconds, however I had 3 more vills with Roman. All civs other than Roman have a hard time not getting housed at 4 and/or 8 pop and keep 50 food coming in every 20 seconds.
The power of Roman would be Tool Age warfare, especially against Assy or Hittite. Slingers with their market upgrade can defeat Assy and Hittite Bowmen easily.
I had a 14:10 Tool with Roman just now that was a 49 villa boom on Nomad Narrows. I made a Stable, Archery, and Market in Tool. I made 1 Scout and researched Woodcutting. I entered Bronze with 1150 Food, 950 Wood, and 5 Docks.
Chances are if this was a Zone game vs. an Assy or Hittite I would have built 3-5 more Barracks in Tool, researched Stone Mining, and start attacking with 10+ Slingers and never stopped making them. I would have had the same Bronze time, only I would have spent 1000+ Food and 900+ in wood/stone on Tool units.
Assy and Hittite also can't deal with Watch Towers that well either in Tool so I probably would have sent woodies to a stone pile and built some cheap Roman towers.
Roman would have a stronger economy going into Tool over Assy and Tool would be (have to be) devastating to the Assy player.
Assy and Hittite would never live to see Bronze if a Roman player did this. It would actually be an easy victory over Assy.
So to simply say Assy is better on Nomad maps because they have a better economy and have a better military than Roman is assuming a little too much about how each civilization would be played on a Nomad Narrows game. Roman has a clear cut advantage in Tool and Iron militaries and Assy has a clear advantage in Bronze. Economies aren't that far seperated on Nomad given the building cost bonus.
Can you survive the Blitzkrieg?