The D'deridex class warbird looks very little like Romulan BoP, which itself was replaced by the D7 in TOS S3. If anything it looks more like the Klingon BoP. So does it make more sense if the D'deridex has a Klingon background than a Romulan one? I know this is a superspecific question but it always stood out to me how you can see a clear lineage of Human ships from the Constitution to the Sovereign, and of Klingon ones from the D7 to the Negh'Var, yet not the same for the Romulans.