I decided to jump right in and start a marathon game on the largest map, easiest setting to start, and picked Germany for the Furor Teutonica. My plan was to start finding and converting barbarians. The only fighting unit I have built was a single scout. It and my starting warrior ended up converting dozens of Barbarian Brutes and, so far, a few archers. I'm concentrating on Honor Policies - really handy to get a notification when a new encampment pops, and I get bonuses against the barbs as well. Then I sent my hordes against my local rivals. I'm only up to 1500 BC, and I've already turned 3 other Civs and 3 city-states into puppet states. I spent a bunch of gold turning a couple of city states into allies, but I'm thinking it might be better to make them puppets as well. By 1000 BC it looks like I'll be the only power on the continent. Sure they'll be bigger problems with this strategy in higher difficulty levels (unhappiness will probably be a real issue), but I think if/when I go to multiplayer, I'll be keeping a close eye on the Germans in the early game.