I realize the Romulan Republic uses a pretty standardized navy of Warbirds, but who's to say they can have a few exotic ships of strictly Reman design floating about - a bit like the Atrox, Kumari or D'kyr mixed in with Starfleet? Reman-specific designs seem especially viable when you've got Obisek rallying a 'freedom force' against the Tal Shiar.
What about the Reman carrier? It's name is the Scimitar.
The Scimitar is a REMAN designed and built ship. Not a romulan ship.