I know this is the case, but that requires the right terrain, as you mention, and they still have an awful research-to-gold ratio. And even with good scales, I would think that money would be an issue, if you want to max recruitment of expensive chariots while building forts and recruiting mages. Unless, of coures, you have a vast area of independent farmland to expand into, but that just happens so rarely to me
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I agree that they are very powerful, and perhaps one of the more straight-forward nations (in some areas), but I do not think they are "over-powered" to the extend that they should be banned. Also, being able to steamroll a bunch of normal AIs is not really the test for over-powerment imo. I would rather hear how people have fared in MP.
I have not had a chance to play them pre-nerf, but I can see how that was way too powerful...