If civ4 has reduced epic empire building, I think it's for the best. Reality generally contradicts the idea that you can sustain such large empires over time, unless you're conquering large swathes of near-empty land that few others would actually want, or that is full of vastly technologically inferior natives that you effectively slaughter (which is also a bit too easy in civ4, as conquering a city and then razing it in a turn is all that's necessary, instead of actually having to raze the populations in every square of that civ's culture, which should also significantly weaken the razing units).
Basically, the ease with which conquest can happen and conquered cities retained beyond a civ's "natural" borders is ridiculous, imo. At the very least it should take large amounts of resources to retain such outliers (other than a few units and some upkeep money).
Also, cities should be able to flip to "barbarian" or back to the previous civ (even if it's been destroyed) much easier, thereby requiring more units to keep control. It's sort of silly that a million+ pop city can be controlled by a unit that can be constructed from a 1,000 pop city, even if that city happened to be the capital of an enemy empire that you just rolled through a few years prior.
Units in general seem to be just too easy to make and maintain.
Basically, the ease with which conquest can happen and conquered cities retained beyond a civ's "natural" borders is ridiculous, imo. At the very least it should take large amounts of resources to retain such outliers (other than a few units and some upkeep money).
Also, cities should be able to flip to "barbarian" or back to the previous civ (even if it's been destroyed) much easier, thereby requiring more units to keep control. It's sort of silly that a million+ pop city can be controlled by a unit that can be constructed from a 1,000 pop city, even if that city happened to be the capital of an enemy empire that you just rolled through a few years prior.
Units in general seem to be just too easy to make and maintain.