I can almost buy Vulcan being successfully occupied
by 2000 soldiers.
Really, with the armaments available to people in the 24th century, 2000 soldiers could probably slaughter hundreds of thousands a day (we're actually supposed to believe this about the Jem'Hadar in WYLB, but I don't for a second--800 million
in a few hours is beyond the logistical capabilities of anything but an occupation force that comes close to matching the population, and then big kill weapons like photon artillery or whatever would've wound up killing their own people!). An occupation force of 2000 could hold most major cities hostage, however.
, on the other hand... about as successful as the Cuban defense of Grenada, except since it was Vulcan, heartland of the Federation, imagine the Cubans sizing a small town on the Florida coast.
I fully agree that the ending of Unification makes almost no sense. There are hundreds of easier ways to provoke a war with the Federation, which is what would've happened after the invasion. Maybe if their plan had been to sneak a suitcase photon torpedo onto Vulcan or something, it would make some sense, but then that
seems cartoonishly evil.