I know everybody has said they are OP. But I feel they are woefully UP. This is because they can't build cities. They get stuck in their era and can never advance. And when the Huns advance, they tend to pick Mongols, and Mongols tend to stay Mongols. So they get way behind because they only have 1 or two cities (a ton of outposts but they don't give stars).

Has anybody else had this issue?

I feel sorry for them. They're so far behind.