Romulan Rhienn Class DestroyerThis is the ship we are talking about
well, i think the neck is ok.. you can see at the norexan (also known as valdore) warbird, that the romulans like these thinn elements.. the warp drives of the norexan seem to fly away every second

most large vessels have the double hull design. We think that small romulan vessels don't have them (revering to the scour, the only small romulan vessel known) and only giant warbirds have them, to demonstrate the glory of the empire in size..
by the way, the norexan, d'deridex, tavara warbirds and the romulan serkas class have double hull designes
only the rhienn, generix, leavhal and talon class vessels don't have.. so it is 50:50