I was always bothered by the assumption that one broadcast would get them through ALL of Federation defense and security measures all the way to a founding member world.
Assuming that they actually reached Vulcan (damned unlikely, but hey! Science Fiction, y'know?) that the 2000 Romulan troops wouldn't have been able to "conquer" Vulcan so much as take huge swaths of the civilian population hostage and force a negotiated settlement. Remember, each of those Romulans is carrying an energy weapon capable of wiping out whole crowds of people (plus whatever other armaments they might have been carrying) and the Vulcan populace is predominantly pacifist. I figured that the Romulan plan was to put enough boots on the ground to make a full out war too costly for the Federation to attempt.
hmm. Really IS a silly plan, once you think about it, isn't it?