How would Starfleet know what a "Romulan" is, in Star Trek 2009?

In TOS, Kirk's Enterprise encounters a Romulan warbird for the first time, after it had destroyed several Starfleet outposts along the Neutral Zone. When they see the ship's captain, they are genuinely surprised that he looks Vulcan. Even Spock is surprised, and he surmises that the Romulans are probably an off-shoot of the Vulcan people who went off-world, possibly because they did not believe that emotions should be completely suppressed. (Logically, he is correct.)

This implies that:

(1) prior to that encounter, humans, Vulcans, and other species in Starfleet and the Federation did not know what a Romulan looks like;

(2) if a Starfleet crew were to have encountered a group of Romulans who do not specifically indicate that they are Romulan, then they would probably conclude that they had encountered a group of Vulcans.

Chronologically, the timeline in Star Trek (2009) is supposed to be identical to the Prime timeline until Nero's arrival and battle with the USS Kelvin. Therefore, Starfleet officers on the Kelvin would know the term "Romulan" (from historically-recorded battles that did not involve view-screen contact) but would not know what one looks like. (Enterprise was very careful not to have any view-screen time between between Archer's crew and the Romulan scout ships that they encountered.)

At no point while communicating with the Kelvin does anyone on Nero's ship say the word "Romulan". Nero's ship, the Narada, would likely bear no resemblance to any historical records of Romulan ships — and any such records would have been decades old even in the Kelvin's time anyway!

So here is something that makes no sense: no one on the Kelvin seems surprised to have been attacked by people who look like Vulcans, and no one asks if they are a Vulcan or not.

Flash forward now to Kirk and company prior to, and during, the Battle of Vulcan. They all seem perfectly fine with the fact that Nero is a Romulan, and even seem to know this before meeting him at Vulcan. At Kirk's age, the Romulan Star Empire would still be pursuing an isolationist policy, well behind the Neutral Zone. Why do they seem so comfortable with the notion of a Romulan?

Prior to meeting Nero, Kirk mentions to Pike on the bridge of the Enterprise that certain aspects of Nero's recent battle with a Klingon fleet mirror the Kelvin's encounter with the Narada. The reports about the battle with the Klingons mentions a massive Romulan ship and Kirk reminds Pike that Pike's own report after the destruction of the Kelvin mentions a massive Romulan ship was the antagonist. How would Pike know at that time that the Narada was a Romulan ship, given all of the facts above?

Is there an explanation for these inconsistencies?