I would have preferred if we'd never seen the Romulans on screen throughout ENT, seeing as how they were to be the faceless enemy. For example in the episodes that feature the Romulan drone and the introduction of the Aenar, they could have either cut all the scenes with the Romulans or just shown the Aenar hooked up to a machine with people talking off camera. Then at the end of the episode, as the crew ponder on who was behind it cut to visual of a planet with the drone approaching flanked by a couple of Romulan birds-of-prey.
Its kind of obvious why we saw Romulus in those episodes, in order to establish the Remans in another branch of the franchise outside of Nemesis and the name Valdore.
Commander Austin Harris, First Officer, Deep Space Nine (by FltCpt. Bossco)
8.01 - Darkest Before Dawn
(Chapter 8 added, 12/09/2015)