Differentiate Romulans and Cardassians

TNG: Romulans are the analogy of a cold war enemy. Strict, authoritarian, powerful, and espionage was a huge thing.

DS9: Cardassians are the analogy of the cold war enemy. They too are strict, authoritarian, powerful, and espionage was a huge thing.

What makes them different? The only thing I can think of, is that the Romulans are more insular and paranoid, while the Cardassians are more imperialistic and egotistic.