Back to the Romulans.
The Romulan Star Empire of the mid-22nd century has roughly disc-shaped vessels with sweeping wing-like structures ending in war nacelles. They appear to utilize either a pulse disruptor or some kind of energy torpedo system (when they fired over the top of Enterprise in "Minefield"). They also appear to possess fairly substantial cloaking technology.
Though we don't truly know the Romulans until two centuries after the founding of the United Federation of Planets, we did see enough in the Enterprise episodes featuring them to see that they clearly had a centralized government (as evidenced by the appearance of a senator), they were militant, and they were technologically-advanced as a race.
I wrote in previous posts that Romulan scientfic advancement was slower than human development, so they are likely slightly more advanced than Starfleet, but less so than the Vulcans. Given their relatively slow scientific development, I am going to assume that they are equally sluggish in their social progress as well. Given that statement, it seems reasonable to assume that the Romulan Senate was likely establish centuries or even millennia earlier, and - since that system has worked so well for them - they have maintained it, making any necessary changes incrementally and over time.
I'm going to also assume that the Romulan Star Empire includes several other planetary systems by the mid-22nd century, given that they have been a spacefaring people for over a thousand years by that point. Since Romulus shares a star system with Remus, I'll also assume that the Remans have been subjugated for nearly the same length of time that the Romulans have been in the system.
Now I know that there are already plenty of features of the Romulan government already established in canon lore, so I'm not going to write anything additional in this thread.
During the Earth-Romulan War, the Romulans had a clear technological advantage, though not a huge one. In MY universe, Starfleet defeated them for three reasons:
1. The humans had support from the Andorians, Tellarites and Vulcans. This support may have been strategic, material, or even direct assistance in combat. I'm saying that Vulcan tacticians aided with planning, the Tellarites with engineering and technological assistance, and the Andorians with ships and personnel.
2. Humans produced ships and equipment faster than the Romulans. Despite their likely superior number of combat vessels and their potentially greater resource chain, the Romulans were used to slow and steady. Once humanity realized the level of the threat, they started cranking out new ships and equipment just like during World War II. In the four years the war lasted, human production hummed along, producing new ships constantly.
3. The Romulans were too arrogant to think that mankind - a relative newcomer in the scheme of things - could possibly best them. For this reason, they underestimated both Earth's capability to make war and its resolve to see it through to the final end.
The Romulans, too assured of their own superiority, failed to make use of their client races as soldiers or starship crewmembers. Consequently, while humanity had multiple allies, the Romulans had only themselves and perhaps some mercenaries to fight. Seeing how Romulans were pathologically secretive, I'm assuming that even those who they brought onboard to fight for them never knew much about them. Thus, the human war machine was likely far larger and far more diverse than the Romulan's military.
Why did the Romulans underestimate Earth? Well, I'm going to guess that the information they collected through their network of spies suggested as much. Reports of their technological capabilities from various sources would have indicated such things as a lack of deflector shields and tractor beams, limited weaponry, and a top speed of warp 5 (or so). While the Romulan ships were likely slower, they were more heavily armed and defended. Also, secrets gleaned from the Vulcans would have likely painted mankind as a race of inept barbarians, so this unintentional misinformation may have fed the Romulans' overconfidence, too.
More later.
mactavish out.
Our country's past progress has been the result, not of the mass mind applying average intelligence to the problems of the day, but of the brilliance and dedication of wise individuals who applied their wisdom to advance the freedom and the material well-being of all of our people.
-Conscience of a Conservative, Barry Goldwater