I think the polish starting area is too strong. Especially if you conquer Germany early. You get Beeswax, Furs, Wine, Silver and Amber with a mere 4 cities as well as Marble, Iron, Copper, Wheat, Cows and grabs. Add in the prolific rivers giving +1 commerce to roughly 1/3 of you're tiles, and you're scary strong.
In general, an early archer or spearman spam will win the game for you. The AI won't bother with many units until after their first settler. If you avoid an early settler, you can build 4 or 5 Spearmen or Archers to take down the 2 or 3 AI Warriors. While rushes are standard in Vanilla civ, they don't always work for a variety of reasons.
What's with the Copper and Iron requirements? It seems like Iron should be revealed with New Mines, not the other way around.