I have a hard time using "balanced" and Roman in the same sentence.

Maybe the technology was "balanced", but the society certainly wasn't. It relied on continual expansion and devolved from a republic into an empire along the way. When the empire couldn't expand anymore, it collapsed and fragmented.

I also don't think their technology level was stable. IMO, they were only about 200 years away from developing a useful steam engine and kicking off their own industrial revolution. They knew the principals, they even had toy steam engines. They were already using both water wheels and windmills to do work when available. They were just missing precision manufacturing techniques to make a steam engine that actually did useful work.