Can't say I've seen even one tank vs. spearman. I have C3C, maybe that makes a difference. The AI seems to prefer to draft over keeping old units. If an AI is so far behind that it actually does have spearmen in era of tanks, I would suspect it would be an extremely simple pushover. OK: Regular tank against elite spearman foritifed in a barricade on a mountain across a river. In this ridiculous scenario, the tank still wins 63.7% of the time. You have to reduce the tank to 1 hp to get your result. IMHO, if you attack any unit, ancient or modern, with a 1 hp tank, you get what you deserve. In any case, the point I'm trying to make is I don't want civ4 reduced to a race to the next level of units. We had that in Civ2 and, frankly, it got pretty boring.