You made a good point here imho, it is very hard to balance a game for every possible playstyle.What you guys need to understand is that we can't call it balance since we have differents perceptions of the game, some for agressive style and others for defensive style.
Of course we will never achieve true equilibrium, but we can lessen the gap between civs that are top 5 on many maps and civs that don't have a situation of being top 5 very often, if ever. Huns, Mayans, Mongols, Aztecs, Celts, Vikings, Spanish are simply to good on to many maps. Civs like Britons, Turks, Koreans, Franks, etc aren't good on enough maps.
As far as balancing units, that one is going to be a heated discussion for quite some time, but balancing civs I think is more unanimously accepted.