Chamboozer
Warlord
Yes the civ4 engine does allow this, you just have to know what to do, and i'm sure Dale knows what he is doing. And that's the whole thing, YOU want an ENJOYABLE game. Besides the fact that this is only what YOU want, making it historically accurate would make it less enjoyable yes, but make it more challenging. So basically what you have just said is that you want an easy game that you can win rather then one that is hard and would make you think.
*sigh*
Yes, the units can be made perfectly historically accurate, and that would balance the units, but the AI would not be able to handle it in a balanced, historically accurate way and would unbalance the gameplay. Look in the thread called unit strengths/cost: realistic to see if you like the ideas there.