In SFB, and SFC too, the Romulans are playing "catch up" with the other races.
I like SFB's refering, from the Gorn's perspective, that the Klingons giving the Romulans MAM based Warp technology, to replace their Impulse Warp technolgy, turned the Romulans from a minor border nusance that could be easily dismissed as laughable, into a serious millitary threat.