If we had decided to make the Romulans the focus of the TNG movies, "Insurrection" and "Nemesis" could have made an excellent duology. Get rid of the Son'a and Ba'Ku and replace them with Romulans and Vulcans, and you've basically got a resolution to the Unification story from the TNG series. You could then build off of it with NEM to create a big Romulan story where we finally make peace with them.
Of course, I do wonder what happened between the end of DS9 and NEM that made the Romulans our enemies again. They were our allies during the Dominion War.
The Remans were, much like the Son'a, a race that came out of nowhere that I was supposed to care about for some reason. We've dealth with the Romulans for so long that introducing this weird slave race of theirs just seemed like it came completely out of left field.