I should not have to read any supplemental material in order to understand the movie, and in the movie Nero's ship came across as way too powerful for a mining ship. Can you imagine a modern mining ship being able to destroy entire fleets of warships from WWI?
Well, can you imagine an oil drilling rig doing the same? She could do that with her bulk alone (plenty of 6 in guns could be mounted there for the classic WWI naval stratagem of defeating quality with quantity), but the plot of the movie involved said drilling rig being equipped with a-bombs intended for some serious seismic work. Bye bye, WWI warfleet...
That a mining rig would be far larger and sturdier than a warship sounds natural to the 21st century audience, since we know that mining is done with those floating steel islands while wars are fought by smallish aluminum ships. That the mining rig would have destructive potential... That's where this red matter thing comes in. And if tiny droplets of it can destroy planets and were intended to destroy stars, then why not starfleets?
The implausible part is not the construction of the Schimitar,but the ownership of it by the Remans.If the vessel was built by Romulans ,they'd have armed sentrys guarding the ship 24-7.
Ol' Spartacus captured a Roman warship, too. The very definition of a slave rebellion is that the slaves overpower their guards somehow. If they do that to their immediate jailers, they can do that to other sets of guards as well. And the guards on the
Scimitar would probably be the same thing as Shinzon's jailers anyway, given that Reman slaves were working on the ship.
This presupposes that Shinzon was in error when he tells Picard that he had the Scimitar built at a secret base.
Why? He was the leader of slaves. Surely it would be plausible for him to have led the construction effort. Under Romulan command, of course, but that's neither here nor there.
Again, nowhere in the movie is it mentioned or even implied that the
Scimitar would have been kept secret from everybody except the Remans. A slightly older script version found at TrekCore makes it more explicit that the Romulan military knew of the ship and her capabilities, but even the aired version makes it perfectly possible to think of this as a Romulan secret project, rather than something done against Romulan wishes.
Timo Saloniemi