I'm not a fan of the ancient Romans. They were violent and superstitious, a colonial empire. They conquered the nearby 'Federation' analog, the Hellenist culture of Greece. Some argue they used science and engineering, but not really. They had enough engineering, mostly military and civil to create their empire, but never expanded on it. They actually didn't much like science, or more properly natural philosophy. Most of the Greek treatises were never translated to Latin, indicating a lack of interest on the part of the Romans.
Violence was a way of life in the Roman empire, from gladiatorial games to numerous conflicts, both civil wars and border wars to expand their empire. Crime was endemic in Roman cities; most people only walked around at night with armed guards.
Romans were extremely superstitious with numerous rituals and incantations to be performed to propitiate the Gods and spirits around them. Some of you were no doubt taught Romans were logical and rational. A few members of the upper class aspired to that, but it was a thin veneer. We think of the Romans like that because the monks of the early middle ages were logical and rational. They valued such qualities and those were the manuscripts they chose to preserve.
Another reason we think of the Romans positively is because of the serious man-crush the scholars of the enlightenment had on the tribe from the Tiber. Everything good about antiquity came from the Romans and scholars over emphasized their virtues and under reported their flaws.
Of course, every analogy has it's limits. I'm brainstorming here and am willing to be accept some modifications to my proposition. Still, the idea of the Romans as the Klingons helps people see them in a different light, perhaps shaking loose some of the adoration moderns have for them.