Much of the game can be decided at a very early stage of you can do the following, even at very high levels. Take the Incan Quechua and kill a couple of barbs, or wild animals and get the promotions, take it as the forest bonus. Get two of them and you can move 2 spaces through the forest. Now find someone to declare war on who has workers. The AI doesn't know you can move 2 spaces so you can easily steal workers and since you have the Quechua advantage against archers they generally won't even attack you. If you have a few Quechuas you can prevent the neighbor from expanding altogether. If they send out a settler you can easily defeat the archer escort(s) and get another worker. This war can go on for thousands of years without war weariness. I have won numerous games even at Immortal level with this tactic and have had to build hardly any of my own workers. Just sit 2 spaces away from the enemy food resource and he will keep sending out workers to improve it and you can keep taking them.