To be sure, our heroes and extras in "Balance of Terror" did not seem to identify the enemy vessel by mere sight of her bows, despite the fact that she was nearly identical to the Romulan ships seen in ENT. Only the bird paint on the belly confirmed their fears that these were indeed the Romulans. So we might surmise that the design in TOS was supposed to be all-new, not seen in the old war.
Scenes cut from "Balance of Terror" would confirm this, with dialogue wherein the heroes think this all-new design is the result of espionage and copying of Starfleet technologies. But then again, those scenes were cut.
Apart from this, we don't know whether the ENT or TOS ships were supposed to represent regular Romulan combatant forces (albeit on special missions) or some sort of exotic mission-specific designs. Scout is as good a guess as battleship or submarine, as far as our rough analogies go. Personally, I'd like to see the various old Romulan ships overall follow a pattern of looking similar to the ENT and TOS ships but being of different sizes - much like we have seen most Klingon ships follow a pattern of a long neck plus aft-mounted wings. Objectively, the truth might be completely different.
Timo Saloniemi
That makes no sense. If someone trespassed against US borders, I doubt they'd send scout ships. When you defend, you send battleships. We do ... as does everyone else. It's just the way you respond to crisis. Scout ships is about exploration.
