The Baktrians are way overpowered?
And you're playing as the Romani, yes?

I haven't seen much of the expansion variants in 0.8, mainly because I'm only on my second real campaign (the first was more of a taster, then I found out the Dacians were getting a few more units for 0.81 so I dropped it) but EB has a lot more variety of results than vanilla (Check out the KH AAR in the gameplay guides section for some really interesting situations). It may look like one of them is destined to become a superpower but really any faction can do well).