Civilization is not an only ancient game. Of course the default game starts at 4.000 BC, etc. But demands realism in this case will force us to consider only 1/5 of the civilizations presented. France is not ancient. The francese and the franks are not the same. The germans and english are not exactly the same thing as the saxons, jutes, and angles. Russia didn`t during the ancient ages, neither the native americans. These were just 'ancient' during the discovery age.
I loved Assyria in the game, I love the ancient civs. I`d love to see the hittites, Israel (the old one), Miccenas, Sumeria, etc. But civ is a game throw the ages, and we have to admit that few of these civs remained, even changed, at the point to survival the test of time.