I think the Babel One arc was a likely precursor to "preserving" Romulan anonymity during the Earth-Romulan war. It's likely they would have shown the Romulans to use a number of drone ships, to prevent discovery. What crewed ships they used probably self-destructed to prevent the allies from gleaning any useful information from the debris.
Davy Jones
"Frightened? My dear, you are looking at a man who has laughed in the face of death, sneered at doom, and chuckled at catastrophe! I was petrified."
-- The Wizard of Oz