Yeah, I read somewhere the original intent was to have a fleet of ships but they needed to cut costs.
In a way, I was kind of glad though. It helped focus the action more on the Enterprise and they still had a great battle scene there. The battle between the Enterprise and the Scimitar, dare I say, was one of the best of the entire film series in fact. You finally got to see the Enterprise fire everything in its arsenal, including little used phaser banks, and the visuals and sound effects were well done. And I really liked the collision scene. Even when the 2 Romulan ships join the fight was well done.
I liked Nemesis, but acknowledge its flaws. But for all that the space battle scene was one of the best of the films.